This study describes the vasorelaxant potential of some pure compounds isolated from Phlomis bracteosa L. marrubiin, phlomeoic acid, and two new constituents labeled as RA and RB. In rat thoracic aortic rings denuded of endothelium, marrubiin, phlomeoic acid, RA, and RB caused relaxation of high K(+) (80 mM) and phenylephrine (1 μM)-induced contractions at the concentration range of 1.0-1000 μg...

Exposure to high oxygen concentration leads to acute lung injury and death in rats after 72 h. The pathophysiology of this phenomenon relies on several mechanisms, including alteration of vascular reactivity, recruitment and activation of neutrophils and alveolar macrophages, production of cytokines and excess production of free radicals. In addition to its potent vasodilating effect, nitric ox...

BACKGROUND Endothelial nitric oxide synthase (eNOS) has previously been detected in the glandular part of the human gastric mucosa. Furthermore, nitric oxide (NO) has been shown to influence gastric secretion in various animal models. The present study was conducted to investigate the influence of exogenously and endogenously derived NO on histamine- and cAMP-stimulated gastric acid secretion i...

We examined the effect of endothelium and lipid emulsion on vasodilation induced by minoxidil at a toxic dose determined underlying mechanism. The effects endothelial denudation, NW-nitro-L-arginine methyl ester (L-NAME), methylene blue, 1H-[1,2,4]oxadiazolo[4,3-a] quinoxalin-1-one (ODQ), glibenclamide, alone or in combination, minoxidil-induced endothelium-intact rat aorta were examined. Addit...

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...

In addition to its effects on vascular tone, nitric oxide (NO) has been suggested to function as a participant in fluid homeostasis affecting interactions between the endothelium and circulating inflammatory cells. The role of NO in the increased microvascular permeability of acute lung injury, however, remains controversial. We investigated the hypothesis that NO opposes increases in pulmonary...

The aim of this study was to investigate the influence of nitric oxide (NO) donors (S-nitroso-L-acetyl penicillamine, spermine-NO complex and sodium nitroprusside) and NO synthase inhibitors (N(omega)-nitro-L-arginine methyl ester, N(omega)-nitro-l-arginine, and (+/-)-2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine) on progesterone production by dispersed bovine luteal cells cultured for 24 h. All...

Prof. José M. López-Novoa, Departamento de Fisiología y Farmacología, Facultad de Medicina, Universidad de Salamanca, Avenida Campo Charro s/n, E-37007 Salamanca (Spain) Dear Sir, NO is synthesized from L-arginine [1] in a reaction catalyzed by nitric oxide synthase (NOS) and is oxidized to nitrite and nitrate in a constant ratio, at a constant pH [2]. Nitrite production has been used as an ind...