Nitric oxide (NO) has been associated with lung inflammation following exposure to silica. L-arginine can be converted to NO and L-citrulline by nitric oxide synthase (NOS), or into urea and L-ornithine by arginase. We tested the hypothesis that after instillation of silica into rat lungs in vivo, lung inflammatory cells increase L-arginine metabolism by both NOS and arginase, which is associat...

The ability of macrophages (Møs) to function within an acidic environment has been shown to depend on cytoplasmic pH (pHi) regulation by vacuolar-type H+ ATPases. Møs metabolize L-arginine via an oxidative pathway that generates nitric oxide, nitrate, and nitrite. Since each of these products could potentially inhibit vacuolar-type H+ ATPases, we investigated the effect of L-arginine metabolism...

In this study, we aimed to investigate the peripheral antinociception effects of specificphosphodiesterase 5 (PDE-5) inhibitor vardenafil on carrageenan-induced nociception in rats,and the role of calcium besides the L-arginine- nitric oxide (NO)- cyclic guanosine monophophate(cGMP) pathway in these effects. Hyperalgesia was induced by the intraplantar injection of 0.1mL fresh carrageenan solut...

In the family of gaseous transmitters, hydrogen sulfide (H2S) is considered as third member beside nitric oxide (NO) and carbon monoxide (CO), which can play physiological role in different organs. The present study was designed to elucidate the antioxidant and free radical scavenging potentials of L-arginnine (a source for endogenous production of NO in vivo) and NaHS (a source H2S) individual...

To investigate whether changes in renal blood flow induced by nondepressor doses of L-arginine, the precursor of nitric oxide, are mediated by a sympathetic neural mechanism, we examined the following in conscious rabbits: (1) the effects of intravenous infusion of L- or D-arginine (15 to 200 mumol/kg per minute) on renal blood flow and renal sympathetic nerve activity with or without intraveno...

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...

effects of intra-central amygdala administration of l-arginine, a nitric oxide precursor, and ng-nitro-l-arginine methyl-ester (l name), a nitric oxide synthase inhibitor, on the morphine-induced sensitization and also on the expression of morphine-induced place conditioning in rats were studied. subcutaneous (s.c.) administration of morphine (2.5, 5 and 7.5 mg/kg) induced place conditioning. r...

Changes in l-arginine metabolism, including increased arginase levels and decreased nitric oxide production, are involved in the pathophysiology of asthma. In this study, using an intranasal mite-induced NC/Nga mouse model of asthma, we examined whether administration of l-arginine ameliorated airway hyperresponsiveness and inflammation by altering l-arginine metabolism. Experimental asthma was...

Exhaled nitric oxide (eNO) is decreased in cystic fibrosis (CF). The effect of oral L-arginine, the precursor of enzymatic nitric oxide (NO) formation, on airway NO in patients with CF was studied. In a pilot study, oral L-arginine was given in a single dose of 200 mg x kg(-1) body weight to eight healthy controls and eight CF patients. Subsequently, the same L-arginine dose was given to 10 pat...