background: during the initial phase of an infection, there is an upregulation of inducible nitric oxide synthase in the macrophages for the production of nitric oxide. this is followed by the recruitment of polymorphonuclear leukocytes (neutrophils) which release arginase. arginase competes with inducible nitric oxide synthase for a common substrate l-arginine. objective: to investigate whethe...

The kinetics of the degradation of the inhibitors of the nitric oxide synthesis, NG-nitro-L-arginine methyl ester and NG-nitro-L-arginine, were examined in human amniotic fluid and umbilical vein blood. The reaction rate constants were calculated or estimated using the time-controlled concentration course of both substances. These concentrations were measured by high-performance liquid chromato...

The effect of nitric oxide synthase (NOS) inhibitors on the brain production of endogenous glutamate receptor antagonist, kynurenic acid, was estimated in vitro. Under standard incubation conditions N(G)-nitro-L-arginine, but not N(G)-nitro-L-arginine methyl ester, up to 5 mM, or 7-nitroindazole, up to 100 microM, inhibited de novo synthesis of kynurenic acid in cortical slices. However, during...

  The involvement of nitric oxide (NO) in the reinforcing properties of opioids was studied by examining the effect of a NO precursor (L-arginine) and NO synthase inhibitor (L-nitro-amino-methyl-ester, L-NAME) on the conditioned place preference (CPP) induced by morphine. The experiment was performed on male albino Swiss- White mice (25 ± 5 g). L-arginine in doses of 100, 200 and 500 mg/kg (i.p...

This study evaluated the effects of progressive nitric oxide (NO) inhibition in the regulation of systemic and regional hemodynamics and renal function in anesthetized dogs. The N(G)-nitro-L-arginine methyl ester group (n = 9) received progressive doses of 0.1, 1, 10, and 50 microg. kg(-1). min(-1). Renal (RBF), mesenteric (MBF), iliac (IBF) blood flows, mean arterial pressure (MAP), pulmonary ...

The study was conducted to find the involvement of Nitric Oxide (NO) using L-arginine, a NO precursor and NG-methyl L-arginine a nitric oxide synthase inhibitor on tolbutamide activity in normal rabbits. L-arginine (25-300 mg/kg, body weight, oral) produced transient and dose dependent hypoglycaemia. When combined with tolbutamide (40 mg/kg, oral) it produced early and prolonged action. The eff...

nucleus accumbens (nac) has been considered as a center for the induction of drug dependence. since a high concentration of the enzyme, nitric oxide synthase (nos) has been found in the nac, and this fact that the role of nitric oxide (no) in acquisition and expression of drug dependence has become clear in recent years, therefore in this study the effects of intraaccumbal injections of l-argin...

background: the presence of nitric oxide (no) in the cuneiform nucleus (cnf) has been previously shown. in this study, ng-nitro-l-arginine methyl ester (l-name) (an inhibitor of no synthase), l-arginine (l-arg) (a precursor of no), and sodium nitroprusside (snp) (a donor of no) were microinjected into the cnf and cardiovascular responses were investigated. methods: seventy male rats were divide...

Nitric oxide (NO) mediates several biological actions, including relaxation of blood vessels, cytotoxicity of activated macrophages, and formation of cGMP by activation of glutamate receptors in cerebellar slices. Nitric oxide synthase (EC 1.14.23.-) immunoreactivity is colocalized with nicotinamide adenine di-nucleotide phosphate diaphorase in neurons that are uniquely resistant to toxic insul...