We report on the modulatory effects of chronic subcutaneous or oral estrogen and LY117018, a selective estrogen receptor modulator, on the release of nitric oxide in rings of rat aorta studied under isometric conditions. Dilator responses to acetylcholine (ACh; 10[8] to 10[-5] M) were obtained in phenylephrine (PE; 2 microM)-contracted aorta, and constrictor dose-response curves to PE (10[-8] t...

OBJECTIVE The study was designed to investigate the role of calcium channels in enhanced angiotensin II (Ang II)-induced contraction in thoracic aortic rings from diabetic rats. METHODS Ang II-induced isometric tension was studied in thoracic aortic rings isolated from control or streptozotocin-induced (8 weeks) diabetic rats. Saturation binding studies at AT1 receptors and L-type calcium cha...

Beta-adrenergic receptor (βAR)-dependent blood vessel relaxation is impaired in older animals and G protein activation has been suggested as the causative mechanism. Here, we investigated the role of βAR subtypes (β1AR, β2AR, and β3AR) and cAMP in maturation-dependent vasorelaxation impairment. Aortic rings from 15 Sprague-Dawley male rats (3 or 9 weeks old) were harvested and left intact or de...

AIM To test the early effect of fructose-induced changes in fatty acid composition and oxidative stress markers in perivascular adipose tissue (PVAT) upon vascular contractility. METHODS Adult male Wistar rats were fed a commercial diet without (CD) or with 10% fructose (FRD) in the drinking water for 3 weeks. We measured plasma metabolic parameters, lipid composition and oxidative stress mar...

Angiotensin-converting enzyme (ACE) inhibitors appear to correct many of the abnormalities associated with the vascular dysfunction found in diabetic patients. In this respect, quinapril is a unique ACE inhibitor with multiple protective effects. The present study was carried out to investigate the effect of intraperitoneal administration of quinapril on the aortic reactivity of streptozotocin ...

The effect of diet-induced, moderate elevation of serum cholesterol on vascular reactivity in isolated rabbit abdominal aortic rings was examined by using a series of vasoconstrictor and vasodilator agonists. Serum cholesterol of rabbits that were fed a cholesterol-free, casein-rich diet for 10 weeks was elevated approximately 4.5-fold compared with values found in control rabbits that were fed...

angiotensin-converting enzyme (ace) inhibitors appear to correct many of the abnormalities associated with the vascular dysfunction found in diabetic patients. in this respect, quinapril is a unique ace inhibitor with multiple protective effects. the present study was carried out to investigate the effect of intraperitoneal administration of quinapril on the aortic reactivity of streptozotocin ...

We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT2R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of r...

OBJECTIVE To evaluate the possible vascular effects of an environment carcinogen benzo(a)pyrene (BaP). METHODS The cytotoxicit of BaP and rat liver S9 (0.25 mg/mL)-activated BaP were examined by MTT assay. Thoracic aortic rings were dissected from Sprague-Dawley rats. Contraction of aortic rings was induced by 60 mmol/L KCl or 10(-6) mol/L phenylephrine (PE) in an ex-vivo perfusion system aft...

Pentamethoxyflavone (PMF) was isolated from the rhizomes of Kaempferia parviflora, a plant that is claimed to have anti-hypertensive effects. We have investigated the activity of the PMF on isolated rat thoracic aortic rings. PMF caused a relaxation of phenylephrine precontracted aortic rings, and this effect was inhibited by N-nitro-L-arginine (LNA), ODQ (guanylyl cyclase inhibitor), or by rem...