The influence of nitric oxide (NO) on anticonvulsant activity of diazepam and clonazepam was examined in the pentetrazole- and electroshock-induced seizure models in mice. Protective efficacy of the threshold dose of diazepam against pentetrazole-induced clonic and tonic seizures, and death was significantly increased by NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) while 7-nitroindaz...

Aim: Acetylsalicylic acid (ASA, aspirin), which is one of the most frequently used drugs in the world, causes severe gastric mucosal injury. Nitric oxide (NO) is synthesized from L-arginine by nitric oxide synthase (NOS). NOS can be inhibited by Nω-nitro-L-arginine methyl ester (L-NAME) and stimulated by supplementing the diet with L-arginine (L-Arg). The aim of this study was to investigate th...

We have reported recently that the renal angiotensin II type 2 (AT2) receptors are upregulated and involved in promoting natriuresis/diuresis in obese but not in lean Zucker rats. In the present study, we tested the hypothesis that there is an enhanced AT2 receptor signaling via NO/cGMP pathway leading to greater inhibition of the Na(+), K(+)-ATPase (NKA) activity in the proximal tubules (PT) o...

BACKGROUND Escherichia coli heat stable enterotoxin (STa) is a major cause of secretory diarrhoea in humans. AIMS To assess the effects of instilling STa into the ileum on remote fluid secretion in the jejunum and colon in rats in vivo by a gravimetric technique. METHODS AND RESULTS Ileal STa (55 ng/ml) stimulated fluid secretion in both ileal and jejunal loops but not in the colon. The flu...

Dopamine (DA) release in the medial preoptic area (MPOA) of the hypothalamus is an important facilitator of male sexual behavior. The presence of a receptive female increases extracellular DA in the MPOA, which increases further during copulation. However, the neurochemical events that mediate the increase of DA in the MPOA are not fully understood. Here we report that glutamate, reverse-dialyz...

The role of platelet-activating factor (PAF) and nitric oxide (NO) as mediators of the effects of tumor necrosis factor-alpha (TNF-alpha) on skeletal muscle contractility was studied in guinea pig extensor digitorum longus (EDL) muscle. TNF-alpha (5-10 ng/ml) reduced contractility at every stimulation frequency (1-200 Hz) and shifted the force-frequency relationship to the right. The role of NO...

BACKGROUND An acetylcholinesterase inhibitor donepezil currently is used to treat patients with Alzheimer disease. However, its direct effect on cerebral blood vessels has not been evaluated. The present study was designed to examine whether donepezil induces acute cerebral arteriolar dilation and whether neuronal nitric oxide synthase contributes to this vasodilator response. METHODS Brain s...

We investigated the effect of the excitatory amino acid (EAA) receptor agonists L-glutamate, N-methyl-D-aspartate (NMDA), (RS)-a-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainic acid on KCl-induced contractions of rabbit tracheal smooth muscle, as well as the role of epithelium and endogenously produced nitric oxide and prostaglandins on these responses. L-Glutamate decreas...

BACKGROUND AND PURPOSE We have previously demonstrated that L-NMMA (NG-monomethyl-L-arginine) selectively inhibits vasodilatation produced by endothelium-derived nitric oxide but not nitrergic nerves in the bovine penile artery. The present study investigated whether L-NMMA had a similar selective action in the bovine ciliary artery. We also investigated whether two recently introduced inhibito...

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...