Nitric oxide synthase activity was studied by means of NADPH-diaphorase activity and nitric oxide synthase immunoreactivity in the main and accessory olfactory bulbs of the frog Rana perezi and the newt Triturus marmoratus. In both species, NADPH-diaphorase staining was observed in all olfactory fibers. Vomeronasal fibers were NADPH-diaphorase-positive in Triturus but they were NADPH-diaphorase...

Endothelium dysfunction may result from increased production of reactive oxygen species and decreased availability of nitric oxide. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (ie, statins) exert cholesterol-independent vasoprotective effects that are mediated, in part, through the inhibition of small G-proteins Rho and Rac. Rho negatively regulates endothelial nitri...

Background—In the normal heart, phosphodiesterase type 5 (PDE5) hydrolyzes cGMP coupled to nitric oxide– (specifically from nitric oxide synthase 3) but not natriuretic peptide (NP)–stimulated guanylyl cyclase. PDE5 is upregulated in hypertrophied and failing hearts and is thought to contribute to their pathophysiology. Because nitric oxide signaling declines whereas NP-derived cGMP rises in su...

Arginine can be metabolized in wounds to nitric oxide and citrulline by nitric oxide synthase or to urea and ornithine by arginase. We investigated the expression of these arginine metabolic pathways over a 3-week period. Groups of 8-10 male Balb/C mice underwent a dorsal skin incision and subcutaneous polyvinyl alcohol sponge implantation. The animals were sacrificed at various times, and spon...

the mechanism by which lead may cause a perturbotion in the nevous system is through the nitric oxide synthase. in this study the effect of lead acetate on the hippocampal constitutive nitric oxide production was studied. the variation in the nitric oxide production may contribute to physiological lead neurotoxicity in vivo. different concentrations of lead acetate (10-9 to 10-6 m), wre added t...

Chronic ethanol consumption is associated with an increased prevalence of hypertension. The mechanisms of this form of hypertension are unknown. Rats fed ethanol for 2 days develop a tolerance to the acute vasoconstrictive effects of ethanol that is believed to be endothelium dependent. We investigated the effects of acute and chronic ethanol exposure on agonist-stimulated nitric oxide synthase...

Systemic inflammation and oxidative stress are features of normal pregnancy and, in excess, contribute to the pathogenesis of preeclampsia. Inflammatory cell activation stimulates uptake of arginine (the precursor for nitric oxide) by transport system y+, expression of one of its genes (CAT-2) together with inducible nitric oxide synthase, leading to nitric oxide production. We investigated whe...

Endothelium dysfunction may result from increased production of reactive oxygen species and decreased availability of nitric oxide. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (ie, statins) exert cholesterol-independent vasoprotective effects that are mediated, in part, through the inhibition of small G-proteins Rho and Rac. Rho negatively regulates endothelial nitri...

Neisseria gonorrhoeae is an obligate human pathogen that causes gonorrhea. We have shown previously that complement receptor 3 and Akt kinase play important roles in mediating cervical infection. At present, there are limited data to indicate how hormonally induced changes to the mucosal epithelia of the female genital tract mediate the course of gonococcal disease. Hence, I have expanded upon ...

BACKGROUND AND PURPOSE Nitric oxide has been implicated as a mediator of glutamate excitotoxicity in primary neuronal cultures. METHODS A number of indicators of brain nitric oxide production (nitric and cyclic guanosine monophosphate [cGMP] concentrations and nitric oxide synthase activity) were examined after bilateral carotid ligation and right middle cerebral artery occlusion in adult rat...