• Biomolecules & Therapeutics
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• v.6 no.3
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• pp.225-231
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• 1998

This studies were performed for investigation of mechanism on central antidiuretic action of L$_{G}$-Nitro-L-arginine (L-NOARG), nitic oxide systhase inhibitor, in dog. Antidiuretic action of L-NOARG infused into the carotid artery was not affected by renal denervation but inhibited by pretreatment with arginine, NO Precusor. Furthermore, L-NOARG inhibited the diuretic action of dopamine induced by hemodynamic development. Above results suggest that antidiuretic actions of L-NOARG mediated by endogenous substances not associated with renal nerve. Therefore, it is demonstrated that those endogenous substances might be associated with NO which mediate the diuretic action of dopamine.e.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.199-207
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• 1998

Ginseng saponin (G5) purified from Panax ginseng, increase renal blood flow in rats. Nitric oxide (NO) is thought to be a substance endogenously released by G5 in preconstricted lungs and cultured endothelial cells. The present study aims to determine whether G5 could stimulate endogenous 1'elease of NO in rat kidney and urine levels of the stable NO metabolites, nitrite (NO,) and nitrate (NO,) and urinary COMP levels were measured 8 hr after a single intraperitoneal injection of GS (200 mg/kg) Into rats. The effects of the WO synthesis inhibitor, Nu-nitro-L-arginine methyl ester, .1nd the NO precursor, L-arginine, on the G5-induced changes were also determined. The activity of NO synthase, as determined by conversion of ('"C)-L-arginine to ('"C)-L-citrulline, in whole kidney, glomeruli and cortical tubules were also investigated. A single injection of GS resulted in endogenous production of NO as reflected by increase in serum and urine levels of N021N03 and urinary cGMP levels, which were inhibited by the addition o ( N-nitro-L-arginine methyl ester and restored fly L-arginine. GS also stimulated the activity of NO synthase in whole kidney as well as glomeruli and cortical tubules, and Nu-nitro-L-arginine methyl tilter significantly prevented this increase. In conclusion, GS stimulates endogenous NO production and thus, may play a protective role 1 11 the kidney by modulating renal blood flow.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.1
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• pp.9-20
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• 2023

The mechanism is unclear for the reported protective effect of hyperbaric oxygen preconditioning against oxidative stress in tissues, and the distinct effects of hyperbaric oxygen applied after stress. The trained mice were divided into three groups: the control, hyperbaric oxygenation preconditioning, and hyperbaric oxygenation applied after mild (fasting) or hard (prolonged exercise) stress. After preconditioning, we observed a decrease in basal levels of nitric oxide, tetrahydrobiopterin, and catalase despite the drastic increase in inducible and endothelial nitric oxide synthases. Moreover, the basal levels of glutathione, related enzymes, and nitrosative stress only increased in the preconditioning group. The control and preconditioning groups showed a similar mild stress response of the endothelial and neuronal nitric oxide synthases. At the same time, the activity of all nitric oxide synthase, glutathione (GSH) in muscle, declined in the experimental groups but increased in control during hard stress. The results suggested that hyperbaric oxygen preconditioning provoked uncoupling of nitric oxide synthases and the elevated levels of GSH in muscle during this study, while hyperbaric oxygen applied after stress showed a lower level of GSH but higher recovery post-exercise levels in the majority of antioxidant enzymes. We discuss the possible mechanisms of the redox response and the role of the nitric oxide in this process.