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Luk’yanova, V. A., T. S. Papina, A. A. Gimadeev, E. V. Sagadeev, and V. P. Barabanov. "Standard formation enthalpies for α-amino acids: L-serine, L-arginine, and L-tyrosine." Moscow University Chemistry Bulletin 66, no. 2 (April 2011): 88–91. http://dx.doi.org/10.3103/s002713141102009x.
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Parfenova, Helena, Alex Fedinec, and Charles W. Leffler. "Role of tyrosine phosphorylation in the regulation of cerebral vascular tone in newborn pig in vivo." American Journal of Physiology-Heart and Circulatory Physiology 276, no. 1 (January 1, 1999): H185—H193. http://dx.doi.org/10.1152/ajpheart.1999.276.1.h185.
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The role of tyrosine phosphorylation was investigated using protein tyrosine phosphatase inhibitors in newborn pigs equipped with a cranial window in vivo. We tested the hypothesis that cyclooxygenase and nitric oxide (NO) synthase are physiological targets for tyrosine phosphorylation in cerebral circulation. Phenylarsine oxide dilated pial arterioles and increased prostacyclin and prostaglandin E2 in cortical periarachnoid fluid; these responses were inhibited by indomethacin. N ω-nitro-l-arginine methyl ester (l-NAME) and N ω-nitro-l-arginine (l-NNA) inhibited the vasodilation to phenylarsine oxide; the effects of NO synthase inhibitors and indomethacin were additive. Cyclooxygenase-mediated vascular responses were assessed using topical application of arachidonic acid. Phenylarsine oxide and sodium orthovanadata potentiated vasodilation and prostanoid synthesis in response to arachidonic acid. N ω-nitro-l-arginine methyl ester and N ω-nitrol-arginine did not affect vasodilation or prostanoid production in response to arachidonic acid, indicating no cross talk between cyclooxygenase and NO synthase. These data indicate that cyclooxygenase and NO synthase are physiological targets for tyrosine phosphorylation in the cerebral circulation of newborn pigs.
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Avila, Marcela A., Stacy L. Sell, Yuji Kadoi, Donald S. Prough, Helen L. Hellmich, Marco Velasco, and Douglas S. Dewitt. "l-Arginine Decreases Fluid-Percussion Injury-Induced Neuronal Nitrotyrosine Immunoreactivity in Rats." Journal of Cerebral Blood Flow & Metabolism 28, no. 10 (July 9, 2008): 1733–41. http://dx.doi.org/10.1038/jcbfm.2008.66.
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Peroxynitrite is a powerful oxidant capable of nitrating phenolic moieties, such as tyrosine or tyrosine residues in proteins and increases after traumatic brain injury (TBI). First, we tested the hypothesis that TBI increases nitrotyrosine (NT) immunoreactivity in the brain by measuring the number of NT-immunoreactive neurons in the cerebral cortex and hippocampus of rats subjected to parasagittal fluid-percussion TBI. Second, we tested the hypothesis that treatment with l-arginine, a substrate for nitric oxide synthase, further increases NT immunoreactivity over TBI alone. Rats were anesthetized with isoflurane and subjected to TBI, sham TBI, or TBI followed by treatment with l-arginine (100 mg/kg). Twelve, 24, or 72 h after TBI, brains were harvested. Coronal sections (10 μm) were incubated overnight with rabbit polyclonal anti-NT antibody, rinsed, and incubated with a biotinylated secondary antibody. The antigen—antibody complex was visualized using a peroxidase-conjugated system with diaminobenzidine as the chromagen. The number of NT-positive cortical and hippocampal neurons increased significantly in both ipsilateral and contralateral hemispheres up to 72 h after TBI compared with the sham-injured group. Remarkably, treatment with l-arginine reduced the number of NT-positive neurons after TBI in both cortex and hippocampus. Our results indicate that l-arginine actually prevents TBI-induced increases in NT immunoreactivity.
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Bae, S. Y., Q. Xu, D. Hutchinson, and C. A. Colton. "Y+ and y+L arginine transporters in neuronal cells expressing tyrosine hydroxylase." Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 1745, no. 1 (August 2005): 65–73. http://dx.doi.org/10.1016/j.bbamcr.2004.12.006.
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Žertová, Miroslava, Jiřina Slaninová, and Zdenko Procházka. "Comparison of the Potency of 8-L-Arginine, 8-D-Arginine and 8-D-Homoarginine Vasopressin Analogs with Substituted Phenylalanine in Position 2." Collection of Czechoslovak Chemical Communications 59, no. 6 (1994): 1439–50. http://dx.doi.org/10.1135/cccc19941439.
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An analysis of the uterotonic potencies of all analogs having substituted L- or D-tyrosine or -phenylalanine in position 2 and L-arginine, D-arginine or D-homoarginine in position 8 was made. The series of analogs already published was completed by the solid phase synthesis of ten new analogs having L- or D-Phe, L- or D-Phe(2-Et), L- or D-Phe(2,4,6-triMe) or D-Tyr(Me) in position 2 and either L- or D-arginine in position 8. All newly synthesized analogs were found to be uterotonic inhibitors. Deamination increases both the agonistic and antagonistic potency. In the case of phenylalanine analogs the change of configuration from L to D in position 2 enhances the uterotonic inhibition for more than 1 order of magnitude. The L to D change in position 8 enhances the inhibitory potency negligibly. Prolongation of the side chain of the D-basic amino acid in position 8 seems to decrease slightly the inhibitory potency if there is L-substituted amino acid in position 2. On the other hand there is a tendency to the increase of the inhibitory potency if there is D-substituted amino acid in position 2.
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Angelova, Hristina, Ekaterina Krumova, Elena Dzhambazova, and Daniela Pechlivanova. "Effects of the antinociceptive dipeptide L-tyrosine-L-arginine (kyotorphin) on the motivation, anxiety, and memory in rats." Folia Medica 63, no. 2 (April 30, 2021): 189–96. http://dx.doi.org/10.3897/folmed.63.e53912.
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Introduction: The endogenous dipeptide L-tyrosine-L-arginine (kyotorphin, KTP) is found in brain structures related to the processing of information for nociception, the control of emotions, and memory formation. Besides the antinociceptive effect of KTP, it has a mild protective activity against the deleterious influence of the brain hypoperfusion and streptozotocin on the behavior and memory. Aim: We aimed to study the effects of the intracerebroventricular injection of effective antinociceptive doses of KTP on the motivational behavior, memory, and blood and hippocampal levels of the carbonylated proteins in healthy male adult Wistar rats. Materials and methods: We used a paw-pressure test for assessment of acute nociception, an open field test for assessment of exploration and habituation to a new environment, elevated plus maze test for the evaluation of anxiety-like behavior, and novel object recognition test for working memory. Carbonylated protein assay was used for the assessment of the oxidative impairment of the proteins. The results were analyzed by ANOVA. Results: The present data showed that all single doses of KTP exerted an antinociceptive effect, but this effect was not observed after chronic administration. Only the highest dose of 100 µg was able to induce anxiolytic and motor inhibiting effects. None of the doses used showed effects on the recognition memory or the level of the carbonylated protein. Conclusion: Our results showed that KTP exerted its antinociceptive effect without affecting negatively the blood and brain carbonylated protein or basic behavioral parameters related to the exploration, motivation, and memory formation in healthy rats.
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Kitsiopoulou, Eudoxia, Apostolia A. Hatziefthimiou, Konstantinos I. Gourgoulianis, and Paschalis-Adam Molyvdas. "Resting Tension Affects eNOS Activity in a Calcium-Dependent Way in Airways." Mediators of Inflammation 2007 (2007): 1–6. http://dx.doi.org/10.1155/2007/24174.
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The alteration of resting tension (RT) from 0.5 g to 2.5 g increased significantly airway smooth muscle contractions induced by acetylcholine (ACh) in rabbit trachea. The decrease in extracellular calcium concentration[Ca2+]ofrom 2 mM to 0.2 mM reduced ACh-induced contractions only at 2.5 g RT with no effect at 0.5 g RT. The nonselective inhibitor of nitric oxide synthase (NOS),NG-nitro-L-arginine methyl ester (L-NAME) increased ACh-induced contractions at 2.5 g RT. The inhibitor of inducible NOS, S-methylsothiourea or neuronal NOS, 7-nitroindazole had no effect. At 2.5 g RT, the reduction of[Ca2+]ofrom 2 mM to 0.2 mM abolished the effect of L-NAME on ACh-induced contractions. The NO precursor L-arginine or the tyrosine kinase inhibitors erbstatin A and genistein had no effect on ACh-induced contractions obtained at 2.5 g RT. Our results suggest that in airways, RT affects ACh-induced contractions by modulating the activity of epithelial NOS in a calcium-dependent, tyrosine-phosphorylation-independent way.
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Luiking, Yvette C., Marcella M. Hallemeesch, Marcel C. van de Poll, Cornelis H. C. Dejong, Wouter J. de Jonge, Wouter H. Lamers, and Nicolaas E. P. Deutz. "Reduced citrulline availability by OTC deficiency in mice is related to reduced nitric oxide production." American Journal of Physiology-Endocrinology and Metabolism 295, no. 6 (December 2008): E1315—E1322. http://dx.doi.org/10.1152/ajpendo.00055.2008.
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The amino acid arginine is the sole precursor for nitric oxide (NO) synthesis. We recently demonstrated that an acute reduction of circulating arginine does not compromise basal or LPS-inducible NO production in mice. In the present study, we investigated the importance of citrulline availability in ornithine transcarbamoylase-deficient spfash (OTCD) mice on NO production, using stable isotope techniques and C57BL6/J (wild-type) mice controls. Plasma amino acids and tracer-to-tracee ratios were measured by LC-MS. NO production was measured as the in vivo conversion of l-[guanidino-15N2]arginine to l-[guanidine-15N]citrulline; de novo arginine production was measured as conversion of l-[ureido-13C-5,5-2H2]citrulline to l-[guanidino-13C-5,5-2H2]arginine. Protein metabolism was measured using l-[ ring-2H5]phenylalanine and l-[ ring-2H2]tyrosine. OTC deficiency caused a reduction of systemic citrulline concentration and production to 30–50% ( P < 0.001), reduced de novo arginine production ( P < 0.05), reduced whole-body NO production to 50% ( P < 0.005), and increased net protein breakdown by a factor of 2-4 ( P < 0.001). NO production was twofold higher in female than in male OTCD mice in agreement with the X-linked location of the OTC gene. In response to LPS treatment (10 mg/kg ip), circulating arginine increased in all groups ( P < 0.001), and NO production was no longer affected by the OTC deficiency due to increased net protein breakdown as a source for arginine. Our study shows that reduced citrulline availability is related to reduced basal NO production via reduced de novo arginine production. Under basal conditions this is probably cNOS-mediated NO production. When sufficient arginine is available after LPS stimulated net protein breakdown, NO production is unaffected by OTC deficiency.
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Pareddy, D. R., and R. I. Greyson. "Effects of amino acids on the development of spikelets in cultured tassels of Zea mays." Canadian Journal of Botany 67, no. 5 (May 1, 1989): 1331–35. http://dx.doi.org/10.1139/b89-177.
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The effects of amino acids on spikelet development in in vitro cultured tassels of Zea mays inbred line Oh43 were studied. Single amino acids had differential effects on growth and differentiation of cultured tassels. While a few amino acids (arginine, lysine, valine, and proline) were stimulatory, most of the amino acids were either ineffective (serine, leucine, glycine, threonine, methionine, phenylalanine, histidine, aspartic acid, and tyrosine) or inhibitory (isoleucine, asparagine, tryptophan, glutamic acid, and alanine), at a concentration of 30 mg/L, to the development of "normal" spikelets and also to tassel growth. A mixture of the stimulatory amino acids at their optimal concentrations (arginine, 15 mg/L; lysine, 60 mg/L; valine, 120 mg/L; proline, 15 mg/L) produced the maximum number of "normal" spikelets, thereby duplicating the effect of an optimum concentration of casein hydrolysate.
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Seth, A., S. Basuroy, P. Sheth, and R. K. Rao. "l-Glutamine ameliorates acetaldehyde-induced increase in paracellular permeability in Caco-2 cell monolayer." American Journal of Physiology-Gastrointestinal and Liver Physiology 287, no. 3 (September 2004): G510—G517. http://dx.doi.org/10.1152/ajpgi.00058.2004.
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Role of l-glutamine in the protection of intestinal epithelium from acetaldehyde-induced disruption of barrier function was evaluated in Caco-2 cell monolayer. l-Glutamine reduced the acetaldehyde-induced decrease in transepithelilal electrical resistance and increase in permeability to inulin and lipopolysaccharide in a time- and dose-dependent manner; d-glutamine, l-aspargine, l-arginine, l-lysine, or l-alanine produced no significant protection. The glutaminase inhibitor 6-diazo-5-oxo-l-norleucine failed to affect the l-glutamine-mediated protection of barrier function. l-Glutamine reduced the acetaldehyde-induced redistribution of occludin, zonula occludens-1 (ZO-1), E-cadherin, and β-catenin from the intercellular junctions. Acetaldehyde dissociates occludin, ZO-1, E-cadherin, and β-catenin from the actin cytoskeleton, and this effect was reduced by l-glutamine. l-Glutamine induced a rapid increase in the tyrosine phosphorylation of EGF receptor, and the protective effect of l-glutamine was prevented by AG1478, the EGF-receptor tyrosine kinase inhibitor. These results indicate that l-glutamine prevents acetaldehyde-induced disruption of the tight junction and increase in the paracellular permeability in Caco-2 cell monolayer by an EGF receptor-dependent mechanism.
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Katusic, Z. S. "Endothelial L-arginine pathway and regional cerebral arterial reactivity to vasopressin." American Journal of Physiology-Heart and Circulatory Physiology 262, no. 5 (May 1, 1992): H1557—H1562. http://dx.doi.org/10.1152/ajpheart.1992.262.5.h1557.
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Experiments were designed to characterize the mechanism of vasopressin action in small arteries of brain stem and cerebrum and to determine the role of L-arginine pathway in reactivity of these vessels to vasopressin. Secondary branches of canine basilar arteries (425 +/- 63 microns ID, n = 6) and middle cerebral arteries (466 +/- 30 microns ID, n = 6) were dissected and mounted on glass microcannulas in organ chambers. Changes in intraluminal diameter of the pressurized arteries were measured using a video dimension analyzer. Vasopressin caused endothelium-dependent relaxation in the brain stem arteries [-log half-maximal effective concentration (EC50) = 9.2 +/- 0.4, n = 5] but not in the branches of middle cerebral arteries. In contrast, bradykinin caused identical endothelium-dependent relaxations in arteries of both regions (-log EC50 = 8.0 +/- 0.2, n = 5, and 7.7 +/- 0.1, n = 4 for brain stem and cerebrum, respectively). Relaxations to vasopressin (but not to bradykinin) were reduced in the presence of V1-vasopressinergic antagonist [1-(beta-mercapto-beta-cyclopentamethylenepropionic acid),2-(O-methyl)tyrosine]arginine vasopressin [d(CH2)5-Tyr(Me)AVP;10(-7) M], pertussin toxin (100 ng/ml), and NG-monomethyl-L-arginine (L-NMMA; 10(-4) M). The inhibitory effect of L-NMMA was prevented by L-arginine (3 x 10(-4) M) but not D-arginine (3 x 10(-4) M). These studies suggest that vasopressin causes endothelium-dependent relaxation in canine brain stem arteries. The effect of the neuropeptide appears to be mediated by activation of endothelial V1-vasopressinergic receptors coupled to nitric oxide synthase. This signal transduction pathway is not functional in endothelial cells of branches of middle cerebral arteries.
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Zhao, Guangfeng, Huiming Zhong, Taiwen Rao, and Zhijun Pan. "Metabolomic Analysis Reveals That the Mechanism of Astaxanthin Improves the Osteogenic Differentiation Potential in Bone Marrow Mesenchymal Stem Cells." Oxidative Medicine and Cellular Longevity 2020 (March 25, 2020): 1–11. http://dx.doi.org/10.1155/2020/3427430.
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At present, little research has been done on the metabolic phenotype of the differentiation of mesenchymal stem cells (MSCs) into osteoblasts. In this study, the effect of astaxanthin on improving osteogenic differentiation potential of mesenchymal stem cells was studied by metabolomics. Results showed that L-methionine, L-tyrosine, and 2-hydroxycinnamic acid were upregulated in MSCs treated with astaxanthin, while L-lysine, L-pipecolic acid, L-histidine, L-arginine, D-fructose, and L-aspartic acid were downregulated in samples treated with astaxanthin. In addition, astaxanthin exhibited a significant dose-dependent relationship with these markers. Metabolic pathway enrichment analysis revealed that AST mainly regulated phenylalanine metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis; and pantothenate and CoA biosynthesis during the process of osteogenic differentiation of MSCs. Furthermore, the staining results showed that astaxanthin could actively promote the osteogenic differentiation of mesenchymal stem cells. These findings clearly indicate that astaxanthin plays an important role in inducing osteogenic differentiation of mesenchymal stem cells. In addition, the changed metabolites can be used to monitor the differentiation process.
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Kalugina, L. V., and K. S. Pavlova. "Pain syndrome in adenomyosis. Finding new pathogenesis links and non-hormonal correction opportunities. Literature review." Reproductive Endocrinology, no. 58 (May 27, 2021): 40–44. http://dx.doi.org/10.18370/2309-4117.2021.58.40-44.
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Adenomyosis is characterized by polymorphism of clinical manifestations and is the cause of chronic pelvic pain associated with endometriosis in 53–80% of cases. Heavy dysmenorrhea in adenomyosis is a key factor that reduces the quality of life and, moreover chronic pain reduces stress resistance and launches the rehabilitation cytokines cascade, which causes exacerbation of endometriosis. Formation of painful syndrome with adenomyosis may be due to: changes in neurohumoral regulation, stimulation of nerves and blood vessels growth and myometrium inflammatory remodeling against the background of circulatory disorders and vascular sclerosis. These processes lead to violation of neuroimmune relationships that determine the increase in the number and sensitivity of nociceptors against the background of the chronic immuno-inflammatory process in endometrials and myometry.Experimental studies have shown that the supraspinal role of the nitric oxide (NO) is to indirect mechanical nociceptive reflexes. The dose-dependent L-arginine role in the pain syndrome formation also was shown; it was found that small doses of L-arginine lead to the activation of nNO-synthase and analgesic effect. Large doses are activated by cotorphine synthase to form a dipeptide of cortorphine (L-tyrosine-L-arginine), which induces the met-enkephalin release and analgesic effect. Individual studies have demonstrated a decrease in the symptoms of urinary pain syndrome during L-arginine treatment, which made it possible to include it into the European Association of Urologists recommendations on the chronic pelvic pain treatment in 2017.Clinical comparative study (2013) of the NO donator (L-arginine) effectiveness in the treatment of endometriosis-associated intermenstrual pelvic pain and dysmenorrhea showed a high efficiency of a 3-month course of combination therapy (dienogest 2 mg + Tivortin 4.2 g). Supplement of basic therapy by NO donator (L-аrginine) has shown a faster reaching the clinical effect on reducing endometriosis-associated symptoms and sustainable maintenance of the result achieved. The multifaceted pharmacological effects of L-arginine directly affect a number of essential factors for the adenomyosis development and progression, which allows using this drug in clinical practice.
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Casella, L., M. Gullotti, S. Poli, M. Bonfà, R. P. Ferrari, and A. Marchesini. "Spectroscopic and binding studies on the stereoselective interaction of tyrosine with horseradish peroxidase and lactoperoxidase." Biochemical Journal 279, no. 1 (October 1, 1991): 245–50. http://dx.doi.org/10.1042/bj2790245.
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The interaction of a series of derivatives of tyrosine with horseradish peroxidase (HRP) and lactoperoxidase (LPO) was studied by using optical difference spectroscopy, c.d. and proton n.m.r. spectroscopy in order to reveal differences in the mode of binding of L-tyrosine and D-tyrosine, which are substrates of but react at different rates with the two peroxidases, to HRP and LPO. All the donor molecules form 1:1 complexes with HRP and LPO, but they display a range of affinities for the enzymes. Whereas D-tyrosine binds to HRP more strongly than does L-tyrosine, the opposite holds for the binding to LPO. The distances of the protons of bound tyrosine molecules from the haem iron atoms of HRP and LPO indicate that the site of binding of these substrates is the same as that of simple phenols. This involves the interaction of the phenol nucleus with a protein tyrosine residue [Sakurada, Takahashi & Hosoya (1986) J. Biol. Chem. 261, 9657-9662; Modi, Behere & Mitra (1989) Biochim. Biophys. Acta 996, 214-225]. However, for the present substrates the additional interaction of the carboxylate group with a protein residue (probably an arginine residue) provides further stabilization for the adducts HRP-D-tyrosine and LPO-L-tyrosine with respect to the corresponding complexes with the opposite enantiomers. The differences in the mode of binding of L-tyrosine and D-tyrosine to HRP and LPO is thus determined by the fact that the spatial arrangement of the interacting protein residues can recognize the chirality of the C(alpha)-CO2- and C(beta)-C6H4OH attachment bonds of the substrates.
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Zavalskaya, T. V., and V. V. Bogdan. "Influence of antianginal therapy and L-arginine on serum essential aminoacids spectrum among patients with unstable angina." Likarska sprava, no. 1-2 (March 26, 2019): 63–68. http://dx.doi.org/10.31640/jvd.1-2.2019(9).
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The patients with unstable angina (UA) were examined using the method of ion exchange liquid-column chromatography. The content of the substitutable amino acids (AA) in blood serum was determined: ornithine, taurine, aspartic acid, serine, glutamic acid, proline, glycine, alanine, cysteine, tyrosine, glutamine. The patients were divided into two groups: І – 37 people who received cardicet, bisoprolol, atoris, enap, acetylsalicylic acid, clopidogrel; ІІ – 38 people, the therapy of which, in addition to the mentioned drugs, included L-arginine (100 ml intravenous for 10 days). The results of the study indicate a different dynamics of changes in the level of substitute AK in serum in patients with NA, who received anti-anginal therapy and anti-anginal therapy with L-arginine. Attention is drawn to the fact that in patients with Group I after treatment, the total amount of replacement AA significantly decreased in comparison with the II group in 1,2 times, but remained unchanged compared with the indicator before treatment. In patients of the ІІ group, the total amount of substitute AK in serum is significantly reduced in comparison with kontrol group in 1.4 times, and compared with the indicator before treatment – in 1.2 times. That is, the inclusion of L-arginine in anti-anginal therapy promotes the enhancement of their intracellular metabolism in conditions of coronary circulatory destabilization. In patients with UA, antianginal therapy which included L-arginine, there was a normalization of such alternating AAs as ornithine, taurine and glycine, which can be considered as compensatory, protective reactions in myocardial ischemia. Thus, L-arginine effectively affects the balance of substitute AA blood plasma in patients with UA.
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Tanaka, Mikiei, Yasuo Mukohata, and Seiji Yuasa. "Utilization of D-amino acids by Halobacterium halobium R1mR." Canadian Journal of Microbiology 35, no. 4 (April 1, 1989): 508–11. http://dx.doi.org/10.1139/m89-078.
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Halobacterium halobium R1mR required L-amino acids such as methionine, leucine, valine, isoleucine, arginine, and lysine for growth. They also grew, with a lag phase of 15 to 20 days, when phenylalanine or tyrosine was omitted from the medium. This represents the first evidence that halophilic bacteria can grow on either D-methionine, D-phenylalanine, D-tyrosine, or D-leucine, each of which was substituted for the opposite enantiomer in the medium.Key words: halobacteria, D-amino acid.
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KUMAI, Toshio, Masami TANAKA, Tomonori TATEISHI, Masako ASOH, and Shinichi KOBAYASHI. "Effects of NG-nitro-L-arginine methyl ester and Arginine on Tyrosine Hydroxylase mRNA in the Adrenal Medulla of Rats." Japanese Journal of Pharmacology 75 (1997): 61. http://dx.doi.org/10.1016/s0021-5198(19)41653-3.
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Shin, Hwa Kyoung, Jeong Hyun Lee, Ki Young Kim, Chi Dae Kim, Won Suk Lee, Byung Yong Rhim, and Ki Whan Hong. "Impairment of Autoregulatory Vasodilation by NAD(P)H Oxidase—Dependent Superoxide Generation during Acute Stage of Subarachnoid Hemorrhage in Rat Pial Artery." Journal of Cerebral Blood Flow & Metabolism 22, no. 7 (July 2002): 869–77. http://dx.doi.org/10.1097/00004647-200207000-00012.
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This study assessed the mechanism(s) by which the autoregulatory vasodilation of rat pial artery in response to acute hypotension during the acute phase of subarachnoid hemorrhage (SAH) was markedly blunted. Increased superoxide production from the cerebral vessels in response to NAD(P)H at 24 hours after SAH + NG-nitro-L-arginine methyl ester (L-NAME) (10 mg/kg) was inhibited by intracisternal administration of a tyrosine kinase inhibitor genistein (10 μmol/L) and Rac inhibitor Clostridium difficile toxin B (1 ng/mL) and a flavoenzyme inhibitor diphenyleneiodonium (10 μmol/L). The expression of gp91phox was enhanced by SAH + L-NAME from 12 to 24 hours, which was inhibited by genistein and toxin B, but not the p22phox. Increased membrane translocation of Rac after SAH + L-NAME was attenuated by both genistein and toxin B, whereas increased tyrosine kinase activity was blocked by genistein, but not by toxin B. The blunted autoregulatory vasodilation to acute hypotension was effectively recovered by genistein and C. difficile toxin B as well as by diphenyleneiodonium. In conclusion, SAH during acute stage causes an increase in NAD(P)H oxidase—dependent superoxide formation in cerebral vessels, which is due to activation of tyrosine phosphorylation-dependent increased expression of gp91phox mRNA and translocation of Rac protein, thereby resulting in a significant reduction of autoregulatory vasodilation.
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Campbell, F. C., Jon G. Houseman, and P. E. Morrison. "A preliminary characterization of alkaline digestive proteases in the posterior midgut of the face fly, Musca autumnalis De Geer." Canadian Journal of Zoology 65, no. 3 (March 1, 1987): 635–39. http://dx.doi.org/10.1139/z87-099.
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Alkaline proteases in the posterior midgut of the face fly, Musca autumnalis De Geer, were identified using specific synthetic substrates and nonspecific substrate azocasein. Identification was confirmed with potential protease activators and inhibitors. Optimal azocasein hydrolysis occurred at pH 8.0 and substrate hydrolysis was inhibited by EGTA (ethyleneglycol-bis-(2-aminoethyl ether)-N,N-tetraacetic acid), tosyl-L-lysine chloromethyl ketone (TLCK), and soybean trypsin inhibitor (STI). Tryptic proteolysis was identified by maximal hydrolysis, at pH 8.0, of trypsin specific substrates BAPNA (benzoyl-DL-arginine-p-nitroanilide) and TAME (tosyl-L-arginine methyl ester). TAME hydrolysis was inhibited by PMSF (phenylmethylsulfonyl fluoride), STI, pepstatin A, and dithiothreitol (DTT), but BAPNA hydrolysis was inhibited only by STI and DTT. Chymotrypsin was demonstrated by maximal hydrolysis of BTEE (benzoyl-L-tyrosine ethyl ester) at pH 8.0 and DTT, PMSF, and STI inhibited hydrolysis of this substrate. Aminopeptidase activity was demonstrated by maximal hydrolysis of leucine-p-nitro-anilide at pH 8.0 and the peptidase was inhibited by o-phenanthroline. Carboxypeptidase A-like enzyme hydrolyzed hippuryl-DL-phenyllactic acid maximally at pH 7.5 and carboxypeptidase B showed maximum hydrolysis of hippuryl-L-arginine at pH 7.0. Both carboxypeptidases were inhibited by EDTA (ethylene diamine tetraacetic acid), EGTA, and DTT and carboxypeptidase A was also inhibited by PMSF.
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Luiking, Yvette C., Marcella M. Hallemeesch, Wouter H. Lamers, and Nicolaas E. P. Deutz. "The role of NOS2 and NOS3 in renal protein and arginine metabolism during early endotoxemia in mice." American Journal of Physiology-Renal Physiology 288, no. 4 (April 2005): F816—F822. http://dx.doi.org/10.1152/ajprenal.00308.2004.
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Previously, we observed an enhanced renal protein synthesis and increased de novo arginine production in the early response to endotoxemia in wild-type Swiss mice (Hallemeesch MM, Soeters PB, and Deutz NE. Am J Physiol Renal Physiol 282: F316–F323, 2002). To establish whether these changes are regulated by nitric oxide (NO) synthesized by NO synthase isoforms NOS2 and NOS3, we studied C57BL6/J wild-type (WT), NOS2-deficient (NOS2−/−), and NOS3-deficient (NOS3−/−) mice under baseline (unstimulated) and LPS-treated conditions. The metabolism of renal protein, amino acid, and arginine was studied at the whole body level and across the kidney by infusing the stable isotopes l-[phenyl-2H5]phenylalanine, l-[phenyl-2H2]tyrosine, l- guanidino-[15N2]arginine, and l-[ ureido-13C,2H2]citrulline. Renal blood flow was measured using radioactive PAH extraction. Under baseline conditions, renal blood flow was significantly reduced in NOS2−/− mice (0.29 ± 0.01 vs. 0.48 ± 0.07 ml·10 g body wt−1·min−1 in WT) ( P < 0.05), and de novo arginine production was lower in NOS2−/− mice. After LPS challenge, renal protein turnover and arginine production increased in all three groups ( P < 0.05), even though renal de novo arginine synthesis did not increase. The expected increase in renal citrulline production and disposal after LPS was not observed in NOS2−/− mice ( P = 0.06). Collectively, these data show that NOS2 is constitutively expressed in the kidney and remarkably functional as it affects renal blood flow and de novo arginine production under baseline conditions and is important for the increase in renal citrulline turnover during endotoxemia. NOS3, in contrast, appears less important for renal metabolism. The increase in renal protein turnover during endotoxemia does not depend on NOS2 or NOS3 activity.
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Ossowicz, Paula, Joanna Klebeko, Barbara Roman, Ewa Janus, and Zbigniew Rozwadowski. "The Relationship between the Structure and Properties of Amino Acid Ionic Liquids." Molecules 24, no. 18 (September 6, 2019): 3252. http://dx.doi.org/10.3390/molecules24183252.
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Ionic liquids based on different l-amino acids (glycine, l-valine, l-leucine, l-isoleucine, l-histidine, l-methionine, l-tyrosine, l-tryptophan, l-arginine, and l-threonine) and different cations (tetrabutylammonium (TBA), tributylmethylammonium (tBMA), didecyldimethylammonium (DDA), (2-hydroxyethyl)trimethylammonium (choline) (Chol), alkyl(C12-C14) dimethylbenzylammonium (benzalkonium) (BA), dodecyltrimethylammonium (DDTMA), hexadecyltrimethylammonium (HDTMA), octadecyltrimethylammonium (ODTMA) and 1-ethyl-3-methylimidazolium (EMIM)) have been synthesized and characterized by NMR and FTIR. Viscosity, specific rotation, surface activity, thermal stability (TG), and phase transformations (DSC) have been determined and compared with available data. Furthermore, benzalkonium, didecyldimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, and octadecyltrimethylammonium amino acid ionic liquids have been shown to exhibit surface activity. The dissolution of cellulose in amino acid ionic liquids (AAILs) composed of various cations was also investigated. Cellulose was only dissolved in EMIM salts of amino acids. In particular, the influence of the cation type on selected physicochemical and spectroscopic properties were discussed. The article is a mini review on amino acid ionic liquids.
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Hubler, L., P. S. Leventhal, and P. J. Bertics. "Alteration of the kinetic properties of the epidermal growth factor receptor tyrosine kinase by basic proteins." Biochemical Journal 281, no. 1 (January 1, 1992): 107–14. http://dx.doi.org/10.1042/bj2810107.
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Previous studies have shown that lysine- and arginine-rich proteins can enhance the activity of tyrosine and serine/threonine protein kinases. However, the kinetics and mechanism of this activation are not fully understood. Therefore we investigated the ability of poly(amino acids) and the arginine-rich protein, protamine, to alter the kinetic properties of epidermal growth factor (EGF) receptor protein-tyrosine kinase activity using immunoaffinity-purified receptor isolated from human epidermoid carcinoma (A431) cells. Poly(L-lysine), poly(L-arginine) and protamine stimulated EGF receptor kinase activity by 3-5-fold at non-saturating doses of ATP and peptide substrate, while poly(L-glutamate) had no effect. Initial kinetic studies demonstrated an increase in the maximum velocity and a decrease in the apparent Km for the peptide substrate angiotensin II in the presence of the basic effectors. Further analysis of the kinetic mechanism by product inhibition revealed that protamine altered the pattern of ADP inhibition towards the peptide substrate but not towards ATP. The change was indicative of the receptor's ability to form an enzyme-angiotensin II-ADP ternary complex in the presence of protamine but not in its absence. In addition, the basic effectors had a substantially decreased influence on the kinase activity of a C-terminally truncated form of the EGF receptor. Thus the changes in kinase activity may be partially mediated by the C-terminal region of the receptor, which contains the sites of receptor self-phosphorylation. These results suggest that the basic domains of proteins can interact with the EGF receptor to induce changes in its kinetic properties, especially with regard to reactant recognition and binding.
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Ilić, Slavica, Jovan Ćirić, and Gordana Gojgić-Cvijović. "The effect of the nitrogen source type on the growth and consumption of crude glycerol by Streptomyces hygroscopicus CH-7." Advanced Technologies 10, no. 1 (2021): 41–45. http://dx.doi.org/10.5937/savteh2101041i.
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In this paper we studied the effect of different amino acids (arginine, tryptophan, tyrosine, and phenylalanine) as nitrogen sources on the growth of actinomycete Streptomyces hygroscopicus CH-7 and the consumption of crude glycerol, obtained as a by-product in the biodiesel production from sunflower oil. The highest biomass concentration (9.5 g/L) was achieved using the basic medium and the medium with tryptophan (9.2 g/L), while the crude glycerol consumption was the highest in the basic medium (5.9 mg/mL) and the medium with phenylalanine (3.3 mg/mL).
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Luiking, Yvette C., Marcella M. Hallemeesch, Wouter H. Lamers, and Nicolaas E. P. Deutz. "NOS3 is involved in the increased protein and arginine metabolic response in muscle during early endotoxemia in mice." American Journal of Physiology-Endocrinology and Metabolism 288, no. 6 (June 2005): E1258—E1264. http://dx.doi.org/10.1152/ajpendo.00485.2004.
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Sepsis is a severe catabolic condition. The loss of skeletal muscle protein mass is characterized by enhanced release of the amino acids glutamine and arginine, which (in)directly affects interorgan arginine and the related nitric oxide (NO) synthesis. To establish whether changes in muscle amino acid and protein kinetics are regulated by NO synthesized by nitric oxide synthase-2 or -3 (NOS2 or NOS3), we studied C57BL6/J wild-type (WT), NOS2-deficient (NOS2−/−), and NOS3-deficient (NOS3−/−) mice under control (unstimulated) and lipopolysaccharide (LPS)-treated conditions. Muscle amino acid metabolism was studied across the hindquarter by infusing the stable isotopes l-[ ring-2H5]phenylalanine, l-[ ring-2H2]tyrosine, l-[ guanidino-15N2]arginine, and l-[ ureido-13C,2H2]citrulline. Muscle blood flow was measured using radioactive p-aminohippuric acid dilution. Under baseline conditions, muscle blood flow was halved in NOS2−/− mice ( P < 0.1), with simultaneous reductions in muscle glutamine, glycine, alanine, arginine release and glutamic acid, citrulline, valine, and leucine uptake ( P < 0.1). After LPS treatment, (net) muscle protein synthesis increased in WT and NOS2−/− mice [LPS vs. control: 13 ± 3 vs. 8 ± 1 (SE) nmol·10 g−1·min−1 (WT), 18 ± 5 vs. 7 ± 2 nmol·10 g−1·min−1 (NOS2−/−); P < 0.05 for LPS vs. control]. This response was absent in NOS3−/− mice (LPS vs. control: 11 ± 4 vs. 10 ± 2 nmol·10 g−1·min−1). In agreement, the increase in muscle arginine turnover after LPS was also absent in NOS3−/− mice. In conclusion, disruption of the NOS2 gene compromises muscle glutamine release and muscle blood flow in control mice, but had only minor effects after LPS. NOS3 activity is crucial for the increase in muscle arginine and protein turnover during early endotoxemia.
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Şakıyan, İffet, Resül Özdemir, and Hatice Öğütcü. "Synthesis, Characterization, and Antimicrobial Activities of New N-(2-hydroxy-1-naphthalidene)-amino Acid (L-Tyrosine, L-Arginine, and L-Lysine) Schiff Bases and Their Manganese(III) Complexes." Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry 44, no. 3 (November 6, 2013): 417–23. http://dx.doi.org/10.1080/15533174.2013.776604.
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Salzman, A., A. G. Denenberg, I. Ueta, M. O'Connor, S. C. Linn, and C. Szabo. "Induction and activity of nitric oxide synthase in cultured human intestinal epithelial monolayers." American Journal of Physiology-Gastrointestinal and Liver Physiology 270, no. 4 (April 1, 1996): G565—G573. http://dx.doi.org/10.1152/ajpgi.1996.270.4.g565.
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We have examined the induction and activity of inducible nitric oxide (NO) synthase (iNOS) in monolayers of DLD-1 cells, an epithelial cell line derived from a human intestinal adenocarcinoma. Induction of iNOS transcription?by a combination of the cytokines interferon-gamma and IL-1 beta was inhibited by genistein, pyrrolidine dithiocarbamate, or dexamethasone and unaffected by pretreatment with ethylene glycol-bis(beta-aminoethyl ether)-N, N,N',N'-tetraacetic acid, basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), or the isoflavone daidzein. iNOS activity and NO synthesis were inhibited by nitro-L-arginine methyl ester, NG-monomethyl-L-arginine, S-methyl-isothiourea sulfate, or aminoethyl-isothiourea, but not by dexamethasone. NO synthesis was potently inhibited by N-alpha-p-tosyl-lysine chloromethyl ketone and hypoxia. In the absence of cytokines no iNOS induction was observed with oxidant stress (H2O2), growth factors (bFGF, EGF), hypoxia or hypoxia reoxygenation. We conclude that in this model of the human intestinal epithelium 1) cytokine-mediated induction of iNOS is Ca2+ independent, weakly steroid sensitive, and may involve the activation of nuclear factor-kappa B and a tyrosine kinase, and 2) iNOS activity is Ca2+ -independent and inhibited by hypoxia, NG-substituted L-arginine analogues, and isothioureas.
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Fukuyama, Naoto, Shunya Takizawa, Hideyuki Ishida, Kiyotaka Hoshiai, Yukito Shinohara, and Hiroe Nakazawa. "Peroxynitrite Formation in Focal Cerebral Ischemia—Reperfusion in Rats Occurs Predominantly in the Peri-Infarct Region." Journal of Cerebral Blood Flow & Metabolism 18, no. 2 (February 1998): 123–29. http://dx.doi.org/10.1097/00004647-199802000-00001.
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Peroxynitrite (ONOO−) exhibits potent neurotoxicity and plays an important role in neu ronal death, but no evidence shows that it is formed in the brain during ischemia or subsequent reperfusion. To detect the formation of ONOO−, we used a hydrolysis/HPLC procedure to measure the formation of 3-nitro-l-tyrosine (NO2-Tyr), which is considered to reflect attack of ONOO− on l-tyrosine residues of cellular components in the brain. Focal ischemia was produced by occluding the right common carotid and right middle cerebral arteries for 2 hours, and the ischemic area was reperfused by reopening the middle cerebral artery. After 2 hours of ischemia, the values of the ratio of NO2-Tyr to l-tyrosine were 0% ± 0%, 0.42% ± 0.13% and 0.29% ± 0.10% in the noninfarct, periinfarct, and core-of-infarct regions, respectively. After 3 hours of reperfusion following 2 hours of ischemia, the ratio in the periinfarct region reached 0.89 ± 0.22%, which was significantly higher than that in the core-of-infarct region (0.35 ± 0.09%). The NO2-Tyr was not detected in 50 mg/kg of N-monomethyl-l-arginine–treated or sham-operated rats. Regional CBF in the periinfarct region decreased to 30.8 ± 15.9 mL/100 g/min during occlusion, but recovered more rapidly than did that in the core-of-infarct region.
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Nakano, Toshihide, Ryuji Tominaga, Ichiro Nagano, Hayato Okabe, and Hisataka Yasui. "Pulsatile flow enhances endothelium-derived nitric oxide release in the peripheral vasculature." American Journal of Physiology-Heart and Circulatory Physiology 278, no. 4 (April 1, 2000): H1098—H1104. http://dx.doi.org/10.1152/ajpheart.2000.278.4.h1098.
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The effects of pulsatility in blood flow on endothelium-derived nitric oxide (EDNO) release in the peripheral vasculature were investigated. The basal and flow-stimulated EDNO release were compared between pulsatile and nonpulsatile systemic flows before and after the administration of NO synthase inhibitor NG-monomethyl-l-arginine (l-NMMA). Peripheral vascular resistance (PVR) was significantly lower in pulsatile flow than in nonpulsatile flow, but this difference disappeared after l-NMMA. The percent increase in PVR by l-NMMA was significantly larger in pulsatile flow. In reactive hyperemia in the hindlimb, the peak flow did not differ; however, both the repayment flow and the duration were significantly larger in pulsatile flow. Percent changes of these parameters by l-NMMA were significantly larger in pulsatile flow. These data indicated that pulsatility significantly enhances the basal and flow-stimulated EDNO release in the peripheral vasculature under in vivo conditions. We also studied the involvement of the Ca2+-dependent and Ca2+-independent pathways in flow-induced vasodilation using calmodulin inhibitor calmidazolium and tyrosine kinase inhibitor erbstatin A. PVR was significantly elevated by erbstatin A but not by calmidazolium, suggesting that flow-induced vasodilation was largely caused by tyrosine kinase inhibitor-sensitive activation of NO synthase.
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BAYDOUN, Anwar R., Samantha M. WILEMAN, Caroline P. D. WHEELER-JONES, Michael S. MARBER, Giovanni E. MANN, Jeremy D. PEARSON, and Ellen I. CLOSS. "Transmembrane signalling mechanisms regulating expression of cationic amino acid transporters and inducible nitric oxide synthase in rat vascular smooth muscle cells." Biochemical Journal 344, no. 1 (November 8, 1999): 265–72. http://dx.doi.org/10.1042/bj3440265.
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The signalling mechanisms involved in the induction of nitric oxide synthase and L-arginine transport were investigated in bacterial lipopolysaccharide (LPS)- and interferon-γ (IFN-γ)-stimulated rat cultured aortic smooth muscle cells (RASMCs). The expression profile of transcripts for cationic amino acid transporters (CATs) and their regulation by LPS and IFN-γ were also examined. Control RASMCs expressed mRNA for CAT-1, CAT-2A and CAT-2B. Levels of all three transcripts were significantly elevated in activated cells. Stimulated CAT mRNA expression and L-arginine transport occurred independently of protein kinase C (PKC), protein tyrosine kinase (PTK) and p44/42 mitogen-activated kinases (MAPKs), but were inhibited by the p38 MAPK inhibitor SB203580, which at 3 μM caused maximum inhibition of both responses. Induction of NO synthesis was independent of p44/42 MAPK activation and only marginally dependent on PKC, but was attenuated markedly by the PTK inhibitors genistein and herbimycin A. SB203580 differentially regulated inducible NO synthase expression and NO production, potentiating both processes at low micromolar concentrations and inhibiting at concentrations of ⩾ 1 μM. In conclusion, our results suggest that RASMCs constitutively express transcripts for CAT-1, CAT-2A and CAT-2B, and that expression of these transcripts is significantly enhanced by LPS and IFN-γ. Moreover, stimulation of L-arginine transport and induction of NO synthesis by LPS and IFN-γ appear to be under critical regulation by the p38 MAPK, since both processes were significantly modified by SB203580 at concentrations so far shown to have no effect on other signalling pathways. Thus, in RASMCs, the p38 MAPK cascade represents an important signalling mechanism, regulating both enhanced L-arginine transport and induced NO synthesis.
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Mésenge, Christian, Christiane Charriaut-Marlangue, Catherine Verrecchia, Monique Allix, Roger R. Boulu, and Michel Plotkine. "Reduction of tyrosine nitration after Nω-nitro-l-arginine-methylester treatment of mice with traumatic brain injury." European Journal of Pharmacology 353, no. 1 (July 1998): 53–57. http://dx.doi.org/10.1016/s0014-2999(98)00432-4.
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Razvodovsky, Y. E., V. Y. Smirnov, Ye M. Doroshenko, N. Ye Maksimovich, and I. N. Semenenya. "Effect of blockade of synthesis of nitric oxide by L-NAME on the level of free amino acids and biogenic amines in the brain cortex of rats with subtotal cerebral ischemia." Proceedings of the National Academy of Sciences of Belarus, Medical series 16, no. 3 (September 16, 2019): 291–97. http://dx.doi.org/10.29235/1814-6023-2019-16-3-291-297.
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Mechanisms of development of ischemic stroke are complex and have not been fully established. The aim of this study was to estimate the changes in the pool of free amino acids and biogenic animes in the brain cortex of rats with subtotal cerebral ischemia (SCI) and treated with L-NAME. Experiment was made on 18 rats: 12 animals were undergoing bilateral filament occlusion of arteries carotid, 6 of them were treated with L-NAME. The analyses of free amino acids levels in the blood plasma extracts were carried out by reversed phase HPLC.Concentrations of several amino acids were elevated during SCI including aspartate, b-alanine, valine and leucine. In contrast, the levels of glutamate, asparagine, treonine, gamma-aminobutiric acid, tyrosine and 5-hydroxiindolylacetate were decreased. The administration of L-NAME partially prevented the imbalance of the amino acids pool due to SCI by normalizing the levels of aspartate, glutamate, asparagine, methionine, gamma-aminobutiric acid, b-alanine, 5-hydroxiindolylacetate. However, the administration of L-NAME has induced an additional imbalance in the amino acids pool in the brain cortex (decrease in the levels of glutamine, histidine, taurine, tryptophan, phenylalanine, tyrosine (in comparison to SCI) and decrease in the levels of treonine and arginine. The imbalance of the amino acids pool induced by the administration of L-NAME during SCI is more severe than the imbalance caused by SCI.
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Saijonmaa, Outi, Tuulikki Nyman, Riikka Kosonen, and Frej Fyhrquist. "Upregulation of angiotensin-converting enzyme by vascular endothelial growth factor." American Journal of Physiology-Heart and Circulatory Physiology 280, no. 2 (February 1, 2001): H885—H891. http://dx.doi.org/10.1152/ajpheart.2001.280.2.h885.
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The role of vascular endothelial growth factor (VEGF), a potent endothelium-specific angiogenic factor, in the regulation of angiotensin-converting enzyme (ACE) in cultured human umbilical vein endothelial cells (HUVECs) was studied. VEGF (0.07–1.2 × 10−6mmol/l) caused a dose-dependent increase in ACE measured in intact endothelial cells and increased the expression of ACE mRNA. The stimulatory effect of VEGF was inhibited by pretreatment of endothelial cells with the tyrosine kinase inhibitor herbimycin (4.35 × 10−5mmol/l). The stimulatory effect of VEGF was potentiated by the selective cGMP phosphodiesterase inhibitor zaprinast (0.1 mmol/l). The nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester (l-NAME; 5.4 mmol/l) suppressed the stimulatory effect of VEGF. The nonselective cyclooxygenase (COX) inhibitor indomethacin (5 μM) and the selective COX-2 inhibitor NS-398 (5 μM) potentiated the stimulatory effect of VEGF, whereas the selective COX-1 inhibitor resveratrol (5 μM) was without effect. ACE induction by VEGF was inhibited by the selective protein kinase C (PKC) inhibitor GF109203X (2.5 × 10−3mmol/l) and by downregulating PKC with phorbol 12-myristate 13-acetate. In summary, VEGF induced ACE in cultured HUVECs. Intracellular events such as tyrosine kinase activation, PKC activation, and increase of cGMP were probably involved in ACE induction by VEGF. Nitric oxide may partially contribute to ACE induction by VEGF. The powerful capacity of VEGF to increase ACE in endothelial cells shown here suggests a synergistic relation between VEGF and the renin-angiotensin system in vascular biology and pathophysiology.
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Orsák, Matyáš, Zora Kotíková, František Hnilička, and Jaromír Lachman. "Effect of drought and waterlogging on saccharides and amino acids content in potato tubers." Plant, Soil and Environment 67, No. 7 (July 13, 2021): 49–57. http://dx.doi.org/10.17221/661/2020-pse.
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The study was focused on the effect of drought and waterlogging stresses in two-year pot experiments in the peat substrate on the content of glucose, fructose and sucrose and free amino acids in potato tubers of four cultivars (yellow-fleshed Laura, Marabel, Milva and blue-fleshed Valfi) after 71 days of exposure to stresses conditions (BBCH 909). Drought and waterlogging increased levels of fructose, glucose, and sucrose in three potato cultivars except for cv. Laura. Drought stress increased l-proline (+248.4%), l-hydroxyproline (+135.3%), l-arginine (+29.97%), l-glutamic acid (+29.09%) and l-leucine (+22.58%) contents in all analysed cultivars. Moreover, the high effect of drought stress on an increase of l-phenylalanine, l-histidine, l-threonine, and total free amino acids content of the cvs. Laura, Valfi and Marabel has been observed. A comparison of the effects of drought and waterlogging stresses on the content of total amino acids showed an increase under drought and a decrease under waterlogging conditions. On average, of all cultivars, waterlogging stress caused an increase of l-tyrosine content, whereas drought stress decrease. In addition, drought stress caused a significant increase of l-proline in all cultivars while waterlogging its decrease. Obtained results confirmed different responses of susceptible or resistant cultivars to abiotic stresses.
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Reichel, Andreas, David J. Begley, and Armin Ermisch. "Arginine vasopressin reduces the blood-brain transfer of l-tyrosine and l-valine: further evidence of the effect of the peptide on the l-system transporter at the blood-brain barrier." Brain Research 713, no. 1-2 (March 1996): 232–39. http://dx.doi.org/10.1016/0006-8993(95)01539-6.
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Kumai, Toshio, Masami Tanaka, Tomonori Tateishi, Sachiko Nakaya, and Shinichi Kobayashi. "Effects of NG-Nitro-L-Arginine Methyl Ester on Tyrosine Hydroxylase activity in the Adrenal Medulla of Rats." Japanese Journal of Pharmacology 73 (1997): 96. http://dx.doi.org/10.1016/s0021-5198(19)44892-0.
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Wang, Yong G., and Stephen L. Lipsius. "Genistein elicits biphasic effects on L-type Ca2+ current in feline atrial myocytes." American Journal of Physiology-Heart and Circulatory Physiology 275, no. 1 (July 1, 1998): H204—H212. http://dx.doi.org/10.1152/ajpheart.1998.275.1.h204.
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A perforated patch recording method was used to determine the effects of genistein (Gen), a protein tyrosine kinase (PTK) inhibitor, on basal L-type Ca2+ current ( I Ca,L) in feline atrial myocytes. Gen (50 μM) elicited biphasic changes in I Ca,L: an initial inhibition (−55 ± 4%; phase 1) followed by a secondary stimulation (34 ± 9%; phase 2) of I Ca,L. Withdrawal of Gen elicited a further potentiation of I Ca,L (152 ± 19%; phase 3) above control ( n = 46). In general, phase 1 inhibition and phase 3 potentiation varied directly with Gen concentration, and phase 2stimulation exhibited biphasic concentration-dependent changes compared with control. When cells were dialyzed using a ruptured patch recording method, Gen elicited only inhibition of I Ca,L; phases 2 and 3 were abolished. Vanadate (1 mM), an inhibitor of protein tyrosine phosphatase, abolished both Gen-induced inhibition and stimulation of I Ca,L. Daidzein (50 μM), a weakly active analog of Gen, exerted no significant effects on I Ca,L, and withdrawal of daidzein failed to potentiate I Ca,L. In a few cells, Gen elicited a prominent vanadate-sensitive stimulation of I Ca,L in the absence of any significant inhibition of I Ca,L. Gen-induced changes in I Ca,L were unaffected by either 100 μM 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetic acid (BAPTA)-acetoxymethyl ester (AM) or 1 μM ryanodine, agents that alter intracellular Ca2+; 4 μM H-89 or 50 μM Rp diastereomer of adenosine 3′,5′-monophosphothioate (RP-cAMPS), inhibitors of protein kinase A (PKA); 0.1 μM calphostin C or 2 μM chelerythrine, inhibitors of protein kinase C (PKC); or 100 μM N G-monomethyl-l-arginine (l-NMMA), an inhibitor of nitric oxide (NO) synthase. We conclude that in feline atrial myocytes, Gen acts via membrane-bound PTKs to inhibit I Ca,L and via cytosolic PTKs to stimulate I Ca,L. Gen-induced changes in I Ca,L are not related to changes in intracellular Ca2+ or to secondary interactions with either PKA, PKC, or NO signaling pathways. These results indicate that in atrial myocytes I Ca,L is regulated by two independent and competing PTK signaling mechanisms.
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Sotelo, C. G., J. M. Franco, S. P. Aubourg, and J. M. Gallardo. "Changes in free amino acids of hake (Merluccius merluccius L.) muscle during frozen storage/Cambios producidos en los aminoácidos libres del músculo de merluza (Merluccius merluccius L.) durante su conservación en estado congelado." Food Science and Technology International 1, no. 1 (February 1995): 19–24. http://dx.doi.org/10.1177/108201329500100103.
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The effect of storage at subzero temperatures (-5°C, -12°C, and -20°C) on hake ( Merluccius merluccius L.) muscle free-amino acid fraction was evaluated. A significant increase in free aspartic acid, serine, threonine, arginine, β-alanine, tyrosine, methionine, valine, phenylalanine, isoleucine, leucine, and lysine was found at -5°C, whereas at -12°C, a significant decrease in free glutamic acid, glycine, methyl-histidine, β-alanine, taurine, alanine, and leucine was the most noticeable. No changes in the free amino acid fraction were observed at -20°C. Activity of different kind of enzymes, aminopeptidases, aminoacid deaminases, and decarboxylases might be involved in the changes observed at -5°C and -12°C.
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Fujita-Yamaguchi, Y., D. B. Sacks, J. M. McDonald, D. Sahal, and S. Kathuria. "Effect of basic polycations and proteins on purified insulin receptor. Insulin-independent activation of the receptor tyrosine-specific protein kinase by poly(l-lysine)." Biochemical Journal 263, no. 3 (November 1, 1989): 813–22. http://dx.doi.org/10.1042/bj2630813.
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Since the studies on tyrosine phosphorylation of calmodulin by the insulin receptor kinase in vitro suggested that protamine and poly(L-lysine) may activate phosphorylation of the receptor beta subunit [Sacks & McDonald (1988) J. Biol. Chem. 263, 2377-2383], we examined the effects of a variety of basic polycations/proteins and polyamines on insulin receptor kinase activity. The insulin receptor purified from human placental membranes was incubated with each basic polycation/protein or polyamine and assayed for tyrosine-specific protein kinase activity by measuring 32P incorporation into the src-related peptide. At a concentration of 1 microM, poly(L-lysine) and poly(L-ornithine) markedly stimulated kinase activity, whereas poly(L-arginine) and histones H1 and H2B inhibited insulin receptor kinase. In contrast, at a concentration of 1 mM, three polyamines (spermine, spermidine and putrescine) did not alter kinase activity. Poly(L-lysine) and poly(L-ornithine) stimulated the insulin receptor kinase by 5-10-fold at concentrations of 0.1-1 microM. Protamine sulphate also showed a significant stimulatory effect at a concentration of 100 microM. Preincubation of the receptor with poly(L-lysine) or poly(L-ornithine) for 20-60 min resulted in maximal kinase activation. Poly(L-lysine), the most effective activator of the receptor kinase, was used to characterize further the mechanisms of the kinase activation. Poly(L-lysine) activates the insulin receptor kinase by increasing the Vmax. without changing the Km. Poly(L-lysine) markedly stimulates the kinase activity of insulin receptor preparations that have lost both basal kinase activity and the ability to be stimulated by insulin. Insulin and poly(L-lysine) also differed in their ability to stimulate the kinase activity of prephosphorylated receptors. Prephosphorylation of the receptors did not affect the stimulation of the kinase by insulin. In contrast, prephosphorylation of receptors resulted in a markedly enhanced ability of poly(L-lysine) to stimulate kinase activity. These studies suggest that the mechanisms by which poly(L-lysine) and insulin activate the kinase are different. In conjunction with other additional evidence, it is suggested that poly(L-lysine) interacts directly with the beta-subunit of the receptor, thereby activating the receptor kinase.
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Ou, Jingsong, Jason T. Fontana, Zhijun Ou, Deron W. Jones, Allan W. Ackerman, Keith T. Oldham, Jun Yu, William C. Sessa, and Kirkwood A. Pritchard. "Heat shock protein 90 and tyrosine kinase regulate eNOS NO· generation but not NO· bioactivity." American Journal of Physiology-Heart and Circulatory Physiology 286, no. 2 (February 2004): H561—H569. http://dx.doi.org/10.1152/ajpheart.00736.2003.
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An increase in the association of heat shock protein 90 (HSP90) with endothelial nitric oxide (NO) synthase (eNOS) is well recognized for increasing NO (NO·) production. Despite the progress in this field, the mechanisms by which HSP90 modulates eNOS remain unclear due, in part, to the fact that geldanamycin (GA) redox cycles to generate superoxide anion ([Formula: see text]) and the fact that inhibiting HSP90 with GA or radicicol (RAD) destabilizes tyrosine kinases that rely on the chaperone for maturation. In this report, we determine the extent to which these side effects alter vascular and endothelial cell function in physiologically relevant systems and in cultured endothelial cells. Vascular endothelial growth factor (VEGF)-stimulated vascular permeability, as measured by Evans blue leakage in the ears of male Swiss mice in vivo, and acetylcholine-induced vasodilation of isolated, pressurized mandibular arterioles from male C57BL6 mice ex vivo were attenuated by Nω-nitro-l-arginine methyl ester (l-NAME), GA, and RAD. Z-1[ N-(2-aminoethyl)- N-(2-ammonoethyl)amino]diazen-1-ium-1,2-dioate (DETA-NONOate), a slow releasing NO· donor, increased vasodilation of arterioles pretreated with GA, RAD, and l-NAME equally well except at 10–5 M, the highest concentration used, where vasodilation was greater in pressurized arterioles treated with l-NAME than in arterioles pretreated with GA or RAD alone. Both GA and RAD reduced NO· release from stimulated endothelial cell cultures and increased [Formula: see text] production in the endothelium of isolated aortas by an l-NAME-inhibitable mechanism. Pretreatment with RAD increased stimulated [Formula: see text] production from eNOS, whereas pretreatment with genistein (GE), a broad-spectrum tyrosine kinase inhibitor, did not; however, pretreatment with GE + RAD resulted in a super-induced state of uncoupled eNOS activity upon stimulation. These data suggest that the tyrosine kinases, either directly or indirectly, and HSP90-dependent signaling pathways act in concert to suppress uncoupled eNOS activity.
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Xu, H. L., D. L. Feinstein, R. A. Santizo, H. M. Koenig, and D. A. Pelligrino. "Agonist-specific differences in mechanisms mediating eNOS-dependent pial arteriolar dilation in rats." American Journal of Physiology-Heart and Circulatory Physiology 282, no. 1 (January 1, 2002): H237—H243. http://dx.doi.org/10.1152/ajpheart.2002.282.1.h237.
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Nitric oxide (NO), derived from the endothelial isoform of NO synthase (eNOS), is a vital mediator of cerebral vasodilation. In the present study, we addressed the issue of whether the mechanisms responsible for agonist-induced eNOS activation differ according to the specific receptor being stimulated. Thus we examined whether heat shock protein 90 (HSP90), phosphatidylinositol-3-kinase (PI3K), and tyrosine kinase participate in ACh- versus ADP-induced eNOS activation in cerebral arterioles in vivo. Pial arteriolar diameter changes in anesthetized male rats were measured during sequential applications of ACh and ADP in the absence and presence of the nonselective NOS inhibitor N ω-nitro-l-arginine methyl ester (l-NAME), the neuronal NOS (nNOS)-selective inhibitor ARR-17477, the HSP90 blocker 17-(allylamino)-17-demethoxygeldanamycin (AAG), the PI3K inhibitor wortmannin (Wort), or the tyrosine kinase blocker tyrphostin 47 (T-47). Only NOS inhibition with l-NAME (not ARR-17477) reduced ACh and ADP responses (by 65–75%), which suggests that all of the NO dependence in the vasodilating actions of those agonists derived from eNOS. Suffusions of AAG, Wort, and T-47 were accompanied by substantial reductions in ACh-induced dilations but no changes in the responses to ADP. These findings suggest that muscarinic (ACh) and purinergic (ADP) receptor-mediated eNOS activation in cerebral arterioles involve distinctly different signal transduction pathways.
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Métais, Caroline, Jianyi Li, Jian Li, Michael Simons, and Frank W. Sellke. "Effects of coronary artery disease on expression and microvascular response to VEGF." American Journal of Physiology-Heart and Circulatory Physiology 275, no. 4 (October 1, 1998): H1411—H1418. http://dx.doi.org/10.1152/ajpheart.1998.275.4.h1411.
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The effects of coronary artery disease (CAD) on human coronary microvascular responses to vascular endothelial growth factor (VEGF) and the alterations of the myocardial expressions of VEGF and its flk-1 and flt-1 receptors were examined in 48 patients. Microvascular studies were performed in vitro with video microscopy. The expressions of VEGF and its receptors were examined using Northern analysis of total mRNA, and the expressions of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) were examined by RT-PCR. VEGF and hepatocyte growth factor (HGF) caused potent relaxations of microvessels. These responses were reduced in the presence of N G-nitro-l-arginine and the tyrosine kinase inhibitor genistein or in microvessels from patients with CAD. Relaxations to substance P and sodium nitroprusside were similar in both groups. The substance P response was abolished in the presence of N G-nitro-l-arginine. The expression of VEGF and its receptors and the expression of cNOS and iNOS were not altered in patients with CAD. In conclusion, VEGF and HGF elicit the release of nitric oxide through activation of tyrosine kinase receptors. CAD is associated with reduced vascular responses to both VEGF and HGF; this is not likely due to a reduced expression of VEGF or flt-1 or flk-1 receptors and not due to a generalized endothelium dysfunction despite the presence of mild hypercholesterolemia in these patients with CAD. These findings may have important implications regarding the efficacy of endogenous and exogenous VEGF in patients with risk factor for CAD.
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Zhang, Yin, Haixia Zhang, Jianfeng Shi, Shoubei Qiu, Qianqian Fei, Fenxia Zhu, Jing Wang, Yiping Huang, Daoquan Tang, and Bin Chen. "Metabolomics Based Comparison on the Biomarkers between Panax Notoginseng and its Counterfeit Gynura Segetum in Rats." Current Pharmaceutical Analysis 16, no. 8 (September 28, 2020): 1121–29. http://dx.doi.org/10.2174/1573412915666190802142911.
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Background: Because of the similar appearance of Gynura segetum and panax notoginseng, the patients often mistakenly use Gynura segetum as Panax notoginseng, which causes serious liver damage. There is no comparative study on the metabolism of Gynura segetum and Panax notoginseng in the literature. This study was conducted to compare the difference between Panax notoginseng and its counterfeit Gynura segetum by using metabolomics method. Methods: In this paper, an ultra performance liquid chromatography coupled to quadrupole time-offlight mass spectrometric(UPLC-Q/TOF/MS) were used to detect the type of endogenous metabolites in urine and plasma of three groups (normal group, ethanol extract of panax notoginseng, decoction of Gynura segetum respectively, and different multivariate statistical analysis methods were established. Results: In this experiment, main urine biomarkers were L-glutamate, L-methionine, cytidine, and Ltyrosine in the Panax notoginseng group, which are phytosphingosine, creatine and sphinganine in the Gynura segetum group. The plasma biomarkers identified in the Panax notoginseng group were arachidonic acid, L-tyrosine, linoleic acid, alpha-linolenoyl ethanolamide and lysoPC (15:0), and in the Gynura segetum group are L-arginine, L-valine, arachidonic acid and LysoPC(18:2(9Z,12Z)). Conclusion: There are significant difference between Panax notoginseng and Gynura segetum in biomarkers from the perspective of metabolomics in the body.
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Rollin, Xavier, Muriel Mambrini, Tarik Abboudi, Yvan Larondelle, and Sadasivam J. Kaushik. "The optimum dietary indispensable amino acid pattern for growing Atlantic salmon (Salmo salar L.) fry." British Journal of Nutrition 90, no. 5 (November 2003): 865–76. http://dx.doi.org/10.1079/bjn2003973.
Full textAbstract:
To determine the optimum indispensable (I) amino acid (AA) balance in Atlantic salmon (Salmo salar L.) fry, a single protocol established for the pig was adapted. The balance was calculated from the reduction in N gain after replacing about 45% of a single IAA by a mixture of dispensable AA in isonitrogenous diets. We confirmed that the mixture of AA simulating the AA pattern of cod-meal protein and gelatine (46:3, w/w) was used with the same efficiency as cod-meal protein and gelatine. From the deletion experiment an optimum balance between the IAA was derived. Expressed relative to lysine=100, the optimal balance was: arginine 76 (se 0·2), histidine 28 (se 2·2), methionine+cystine 64 (se 1·7), phenylalanine + tyrosine 105 (se 1·6), threonine 51 (se 2·4), tryptophan 14 (se 0·7), valine 59 (se 1·7). No estimates were made for isoleucine and leucine. Expressed as g/16g N, the optimal balance was: arginine 4·0 (se 0·0), histidine 1·5 (se 0·1), lysine 5·3 (se 0·2), methionine+cystine 3·4 (se 0·1), phenylaline+tyrosine 5·6 (se 0·1), threonine 2·7 (se 0·1), tryptophan 0·7 (se 0·0), valine 3·1 (se 0·1). This AA composition is close to that of the Atlantic salmon whole-body, but using it as an estimation of the IAA requirements may lead to an overestimation of the branched-chain AA requirements and an underestimation of aromatic and S-containing AA requirements. The results are discussed in accordance with the key assumptions associated with the model used (broken-line model, IAA efficiencies and maintenance requirements).
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Konopleva, Marina Y., Philip L. Lorenzi, Sanaz Ghotbaldini, Yoko Tabe, Tianyu Cai, and Stefano Tiziani. "Contribution of Amino Acid Metabolism to Hematologic Malignancies." Blood 132, Supplement 1 (November 29, 2018): SCI—10—SCI—10. http://dx.doi.org/10.1182/blood-2018-99-109469.
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Abstract Tumor cells rewire metabolic pathways to meet the high metabolic demands of proliferation, frequently developing auxotrophy to specific amino acid(s) (AAs) required to satisfy protein biosynthesis. Thus specific metabolic inhibitors or AA-depleting enzymes have been developed and tested as cancer therapeutics. For example, depletion of asparagine by bacterial L-asparaginase (ASNase) has proven efficacious against hematologic malignancies, especially leukemia and lymphoma, by starving tumors lacking asparagine synthetase (ASNS). We and others have reported that the glutaminase (GLS) activity of ASNase is required for anticancer activity against ASNS-positive leukemia cell types in vitro.1 In vivo, we have found that durable response to ASNase in pre-clinical models of leukemia also requires glutaminase activity, even against ASNS-negative leukemia models; a glutaminase-deficient mutant of ASNase yielded subsequent leukemia recurrence. We speculate that the underlying anti-leukemia mechanism mediated by ASNase glutaminase activity involves a deeper depletion of asparagine within the tumor microenvironment, since ASNS in nearby cells (adipocytes, mesenchymal stromal cells, etc.) can use glutamine as a precursor for asparagine synthesis. Nevertheless, since L-glutamine depletion is thought to cause the significant side effects of ASNase, enzyme variants with reduced glutaminase coactivity are being developed and tested. Another viable therapeutic strategy involving glutamine starvation via GLS inhibitor has shown significant pre-clinical activity in acute myeloid leukemia (AML) and multiple myeloma (MM) models; this approach is synergistic with hypomethylating agents and BCL2 inhibitors in AML, and with proteasome inhibitors in MM. Recent findings highlight the switch to glutamine metabolism as a metabolic dependency of tyrosine kinase-driven AML, and targeting GLS in conjunction with tyrosine kinase inhibition has been proposed.2 Targeting arginine metabolism has been shown to be another viable therapeutic strategy. Arginine (ARG) depletion using pegylated arginine deaminase (ADI-PEG 20) or pegylated arginase (PEG-ARGase), the 2 critical enzymes of the ARG metabolism/urea cycle, reduced leukemia tumor burden in AML models characterized by low arginosuccinate synthetase (ASS) and high uptake of ARG. However, recently reported Phase I/II clinical trials of recombinant PEG-arginase and of ADI-PEG 20 showed minimal efficacy in relapsed/refractory AML and in solid tumors despite efficient depletion of arginine and low ASS1 expression in tumors, indicating that depletion of arginine alone is insufficient for clinical activity. As a final example of AA metabolic pathways targeted in the treatment of hematologic malignancies, exogenous L-cysteine is required for the synthesis of glutathione for antioxidant cellular defense. In pre-clinical studies, multiple malignancy subtypes were sensitive to cysteine and cystine degradation by an engineered human cyst(e)inase enzyme, including AML, acute lymphocytic leukemia, poor-risk chronic lymphocytic leukemia (CLL), and MM.3 In all therapeutic strategies targeting AA metabolism, the tumor microenvironment may contribute to resistance. For example, bone marrow stromal cells efficiently import cystine, convert it to cysteine, and transport it to CLL cells, facilitating leukemia chemoresistance. Mesenchymal stromal cells and bone marrow adipocytes secrete asparagine and glutamine, respectively, and protect leukemia cells from ASNase cytotoxicity. Recent insights into the immune tumor microenvironment highlight interplay between tumor, AAs, and immune cell functions. Some AAs, such as arginine and glutamine, are essential nutrients for immune cell proliferation and metabolism; excessive tumor consumption of glutamine, or secretion of arginase by myeloid-derived suppressor cells or AML blasts, may deprive immune cells, impair T cell proliferation, and induce immunosuppressive phenotypes. GLS inhibitors that block glutamine consumption and arginase inhibitors that increase plasma arginine, increase availability of their respective target nutrients for immune cells and are, therefore, being explored in ongoing clinical trials as monotherapies and in combination with anti-PD1 blockade. Chan WK, Lorenzi PL, Anishkin A, et al. The glutaminase activity of L-asparaginase is not required for anticancer activity against ASNS-negative cells. Blood. 2014;123:3596-3606. Gallipoli P, Giotopoulos G, Tzelepis K, et al. Glutaminolysis is a metabolic dependency in FLT3(ITD) acute myeloid leukemia unmasked by FLT3 tyrosine kinase inhibition. Blood. 2018;131:1639-1653. Zhang W, Trachootham D, Liu J, et al. Stromal control of cystine metabolism promotes cancer cell survival in chronic lymphocytic leukaemia. Nat Cell Biol. 2012;14:276-286. Disclosures Konopleva: Stemline Therapeutics: Research Funding. Lorenzi:Erytech Pharma: Consultancy; NIH: Patents & Royalties.
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Wang, Hua Jing, Jin Li, and Liang Huan Wu. "Growths and Concentrations of Mineral Elements of Pakchoi (Brassica chinensis l.) as Affected by Nitrogen Sources." Advanced Materials Research 726-731 (August 2013): 127–30. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.127.
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A hydroponic experiment was carried out to determine influences of partial replacement of nitrate by ammonium and 20 amino acids of alanine (Ala), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), phenylalanine (Phe), tryptophane (Trp), methionine (Met), aspartic acid (Asp), glutamic acid (Glu), lysine (Lys), arginine (Arg), histidine (His), glycine (Gly), serine (Ser), threonine (Thr), cysteine (Cys), tyrosine (Tyr), asparagines (Asn) and glutamine (Gln) on growths and concentrations of mineral elements of pakchoi (Brassica chinensis L.). Most of amino acids inhibit shoot growths of pakchoi. Different amino acids have various effects on concentrations of calcium (Ca), manganese (Mn), magnesium (Mg), iron (Fe), copper (Cu) and zinc (Zn) in shoots of pakchoi. There are differences in shoot fresh weights, dry weights and concentrations of mineral elements of pakchoi supplied with amino acids and ammonium.
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Czaja, Malgorzata, Ewa Konieczna, Bernard Lammek, Jiřina Slaninová, and Tomislav Barth. "Analogs of Arginine-Vasopressin Substituted in Position 2 with L-4-Cl-Phenylalanine or D-Phenylglycine." Collection of Czechoslovak Chemical Communications 58, no. 3 (1993): 675–80. http://dx.doi.org/10.1135/cccc19930675.
Full textAbstract:
Eight new compounds were designed, synthesized and bioassayed as a part of our studies on the structure-activity relationship of arginine-vasopresine (AVP) analogs. Tyrosine in position 2 of AVP, dAVP, [Cpp1]AVP and [Cpp1,Val4]AVP was substituted by L-4-chlorophenylalanine (4-Cl-Phe) or D-phenylglycine [D-Gly(Phe)] and the effect of these changes on agonistic/antagonistic activity in uterotonic and pressor test was followed. All but one of these analogs were found inhibitory in uterotonic test, however in most cases their potency was fairly low. As to the pressor activity the agonistic potency of the 4-Cl-Phe substituted analogs was essentially the same as having 4-F-Phe in position 2. As far as the potency of antagonists is concerned, 4-Cl-Phe peptides showed significantly higher potency than the 4-F-Phe analogs. All compounds containing D-phenylglycine in position 2 were inactive in the pressor test.
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Post, Laura L., Regina Schuel, and Herbert Schuel. "Evidence that hatching enzyme of the sea urchin Strongylocentrotus purpuratus is a chymotrypsin-like protease." Biochemistry and Cell Biology 66, no. 11 (November 1, 1988): 1200–1209. http://dx.doi.org/10.1139/o88-137.
Full textAbstract:
The sea urchin blastula secretes a hatching enzyme (HE) that dissolves the fertilization envelope. HE was collected from the supernatant seawater of cultures of hatched Strongylocentrotus purpuratus blastulae, and concentrated 20 times by ultrafiltration. The proteolytic activity of HE using casein as substrate was inhibited by the chymotrypsin inhibitors, chymostatin and N-tosyl-L-phenylalanine chloromethyl ketone. The activity was not inhibited by inhibitors (antipain, elastatinal, pepstatin, phosphoramidon, soybean trypsin inhibitor, and Nα-p-tosyl-L-lysine chloromethyl ketone) of other types of proteases. HE did not hydrolyze the synthetic trypsin substrate, α-N-benzoyl-L-arginine ethyl ester, but did hydrolyze the synthetic substrate of chymotrypsin, N-benzoyl-L-tyrosine ethyl ester (BTEE). The BTEEase activity of HE was completely inhibited by the chymotrypsin inhibitors chymostatin and 2-nitro-4-carboxyphenyl N,N-diphenylcarbamate (NCDC). Chymostatin inhibited the natural hatching of sea urchin blastulae. Application of HE to freshly fertilized sea urchin eggs, 2 h after insemination, caused premature dispersal of the hardened fertilization envelope. Chymostatin and NCDC inhibited HE-induced lysis of the fertilization envelope, while inhibitors of other types of proteases were ineffective. These data suggest that sea urchin HE is a chymotrypsin-like protease we call "chymostrypsin."
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Helilusiatiningsih, Nunuk. "IDENTIFIKASI SENYAWA KIMIA PADA BUAH SEGAR TERUNG POKAK (Solanum torvum) DENGAN METODE LCMS." Journal of Food Technology and Agroindustry 3, no. 1 (February 23, 2021): 1–12. http://dx.doi.org/10.24929/jfta.v3i1.1179.
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The content of antioxidant compounds in pokak eggplant (Solanum torvum) had the potential as an herbal medicine and was consumed by the world population. The research objective was to study the chemical compound content of the LCMS method. Experimental design with fresh fruit extraction of pokak eggplant using 95% ethanol solvent. The parameters measured were the chemical components found in fresh fruit. The results of analysis of chemical compounds include Choline, Proline, Bis (2-ethylhexyl) phthalate, BMK ethyl glycidate, 4- Methoxycinnamic acid, chlorogenic acid, 7- Hydroxycoumarine, Trigonelline, 1- Vinylimidazole, Pipecolic acid, L- (+) - Arginine- Stearoylglycerol, Caffeine, Cetrimonium, l- Pyroglutamic acid, Erucamide, Muscone, Cucurmin, Stearamide, Betulin, Acetophenone, Ethyl oleate, SSR146977, D - (+) - Maltose, M-144, Monoolein, L-ide, Histidine, Tomatidine, Oleamide Hexadecanamide, Isoleucine, DIPEA, L- Aspartic acid, Octadecanimine, Maltol, 1-Linoleoyl glycerol, 3- Hydroxy-L- proline, Sakuranin, Leucylprolin, Diaminopimelic acid, Nervonic acid, Nootkatone, Caffeic acid, 5-Hydroxymethyl , Methyl cinnamate, Octyl decyl phthalate, 1-Aminocyclohexanecarboxylic acid, Glycerophospho-N-palmitoyl ethanolamine, 4-Methoxybenzaldehyde, Methyl palmitate, Cyclohexyl, phenyl ketone, Esculin, n-Pentyl isopentyl phthalate, - 6 -Ketoprostaglandin F1α, N, N-Dimethylsphingosin e, α-Eleostearic acid, cis-12-Octadecenoic acid methyl ester, Oleoyl ethanolamide, Citral, L-Tyrosine, XLR-11, Isovanillic acid, 1-Tetradecylamine, Isoquinoline, Calocarpin, Sedanolide, N-Acetyltyramine, Testosterone isocaproate , 2-Methyl-S-benzothiazole, 1-Aminocyclohexanecarboxylic acid, 4-Methylumbelliferyl-α-D-glucopyranoside, Dodecyltrimethylammonium, cis, cis-Muconic acid, 6-Ketoprostaglandin 4-octopamine, Lupeol, N-FeroyETl, [4- (4-Hydroxy-3-methoxyphenyl) tetrahydro-1H, 3H-furo [3,4-c] furan-1-yl] -2-methoxyphenyl hexopyranoside.
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Nakaike, R., H. Shimokawa, M. K. Owada, O. Tokunaga, H. Yasutake, T. Kishimoto, C. Imada, T. Shiraishi, K. Egashira, and A. Takeshita. "Vanadate causes synthesis of endothelium-derived NO via pertussis toxin-sensitive G protein in pigs." American Journal of Physiology-Heart and Circulatory Physiology 271, no. 1 (July 1, 1996): H296—H302. http://dx.doi.org/10.1152/ajpheart.1996.271.1.h296.
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The effects of sodium orthovanadate, an inhibitor of protein tyrosine phosphatases, on the endothelial nitric oxide (NO) pathway were studied in vitro. Vanadate caused endothelium-dependent relaxations in isolated porcine coronary arteries, which were abolished by N omega-nitro-L-arginine methyl ester. The relaxations were also abolished by pertussis toxin, an inhibitor of certain G proteins. Tyrosine kinase inhibitors, genistein and alpha-cyano-3-ethoxy-4-hydroxy-5-phenyl-methylcinnamamide (ST-638), significantly attenuated the vanadate-induced relaxations. Vanadate also caused pertussis toxin-sensitive, endothelium-dependent relaxations in isolated porcine renal and femoral arteries and jugular veins. Immunoblots, using an antibody to phosphotyrosines and to c-Src in native porcine aortic endothelial cells, respectively, showed that vanadate induced an elevation of phosphotyrosine proteins and a decrease in the amount of the active form of c-Src family kinases; both changes were markedly suppressed by cotreatment with ST-638. These results indicate that in porcine blood vessels, vanadate causes a synthesis of endothelium-derived NO for which endothelial tyrosine kinases and pertussis toxin-sensitive G protein are considered to be closely involved.
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Hrčková, M., M. Rusňáková, and J. Zemanovič. "Enzymatic hydrolysis of defatted soy flour by three different proteases and their effect on the functional properties of resulting protein hydrolysates." Czech Journal of Food Sciences 20, No. 1 (November 18, 2011): 7–14. http://dx.doi.org/10.17221/3503-cjfs.
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Commercial defatted soy flour (DSF) was dispersed in distilled water at pH 7 to prepare 5% aqueous dispersion. Soy protein hydrolysates (SPH) were obtained by enzymatic hydrolysis of the DSF using three different proteases (Flavourzyme 1000 L, No-vozym FM 2.0 L and Alcalase 2.4 L FG). The highest degree of hydrolysis (DH 39.5) was observed in the presence of protease Flavourzyme. SPH were used for measuring functional properties (foaming stability, gelation). Treatment with Flavourzyme improved foaming of proteins of DSF. Foaming stability was low in the presence of Novozym. Proteases treated DSF showed good gelation properties, mainly in the case of treatment with Flavourzyme. SDS-PAGE analysis showed that after enzyme ad-dition to the 5% aqueous dispersion of DSF each enzyme degraded both b-conglycinin and glycinin. In general, the basic polypeptide from glycinin showed the highest resistance to proteolytic activity. The most abundant free amino acids in the hydrolysates were histidine (30%), leucine (24%) and tyrosine (19%) in the case of the treatment with proteases Alcalase and Novozym, and arginine (22.1%), leucine (10.6%) and phenylalanine (12.9%) in the case of the treatment with Flavourzyme.