angiotensin-converting enzyme (ace) inhibitors including quinapril could exert a protective effect on cardiovascular system through endothelial system in normoglycemic and diabetic rats. the present experimental work was designed to study the vascular reactivity of aortic ring segments isolated from streptozotocin (stz)-diabetic rats treated for 4 weeks with nitro-l-arginine-methyl ester (l-nam...

The renin-angiotensin system regulates cardiovascular physiology via angiotensin II engaging the angiotensin type 1 or type 2 receptors. Classic actions are type 1 receptor mediated, whereas the type 2 receptor may counteract type 1 receptor activity. Angiotensin-converting enzyme 2 metabolizes angiotensin II to angiotensin-(1-7) and angiotensin I to angiotensin-(1-9). Angiotensin-(1-7) antagon...

Essential hypertensive patients show a reduced nitric oxide availability secondary to oxidative stress generation in peripheral microcirculation. Cyclooxygenase (COX) contributes to reduce nitric oxide availability. We assessed the possible vascular sources of oxidative stress, including COX-1, COX-2, and nicotinamide adenine dinucleotide phosphate oxidase, as determinants of endothelial dysfun...

Objective(s) Single injection of naloxone, a selective antagonist of morphine, prior to the drug conditioning testing was used to investigate on morphine dependence. Materials and Methods Conditioning to morphine (2.5-10 mg/kg, s.c.) was established in adult male Wistar rats (weighing 200-250 g) using an unbiased procedure. Nitric oxide agents were microinjected into the central amygdala pri...

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...

Mice with a collecting duct-specific deletion of endothelin-1 are hypertensive and have impaired Na excretion. Because endothelin-1 activates NO synthase (NOS) in the collecting duct, we hypothesized that impaired renal NO production in knockout mice exacerbates the hypertensive state. Control and knockout mice were treated chronically with N(G)-nitro-l-arginine methyl ester, and blood pressure...

1. The role of nitric oxide as mediator of the vascular alterations present in different models of experimental liver cirrhosis is controversial. In the present study, we evaluated the role of nitric oxide and that of the endothelium in the response to phenylephrine and acetylcholine of isolated aortic rings from chronic bile duct-ligated (29 days) rats and their corresponding controls. Experim...