The effects of constrictor prostanoid (CP) pathway inhibitors on vascular reactivity to vasopressin (VP) and phenylephrine (PE) were examined in thoracic aortas of male, female, and ovariectomized (OVX) female Sprague-Dawley rats. Maximal contractile response of control (Cont) aortas to VP was markedly higher in females (3,885 +/- 332 mg/mg ring wt) than in males (810 +/- 148 mg). Indomethacin ...

In canine cutaneous veins, cooling augments the contractile responses evoked by sympathetic nerve stimulation despite a cooling-induced reduction in the release of norepinephrine. With exogenous norepinephrine, the increased responsiveness observed during cooling results from enhanced sensitivity of the postjunctional alpha-2 adrenoceptors. The present experiments were performed to analyze the ...

ATP-sensitive potassium (KATP) channel openers have a relaxation effect due to the lower cellular membrane potential and inhibit calcium influx. There has been considerable interest in exploring KATP channel openers in the treatment of various diseases such as cardiovascular, cerebrovascular, and urinary system disease and premature labor. The purpose of this study was to synthesize 3,3,6,6-tet...

Objective: The use of drugs with herbal origin is increasing for treatment of gastrointestinal (GI) disorders. Rosa damascena (R. damascena) is a well-known plant suggested to have beneficial effect on GI system. In this study, the effect of aqueous fraction of R. damascena on the contractionsofisolated guinea pig ileum was investigated. Materials and Methods: Aqueous fraction of plant was obta...

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 response of pulmonary arteries to endothelin-1 (ET-1) changes with age in normal pigs and is abnormal in pulmonary hypertension. The purpose of this study was to determine if the same is true of the pulmonary veins. We studied the wall structure and functional response to ET-1 in pulmonary veins from normal pigs from fetal life to adulthood and from pigs subjected to chronic hypobaric hypox...

ANG II type 2 receptor (AT(2)) is upregulated in failing hearts, but its effect on myocyte contractile function is not known. We measured fractional cell shortening and intracellular Ca(2+) concentration transients in left ventricular myocytes derived from transgenic mice in which ventricle-specific expression of AT(2) was driven by the myosin light chain 2v promoter. Confocal microscopy studie...

background: there are controversial reports about the exact mechanisms of lead-induced hypertension, but many factors such as alteration in the responsiveness of cardiovascular system to endogenous substances including catecholamines could be one of the mechanisms involved. in present study, the effect of exposure to 100 ppm lead acetate by drinking water (in the periods of 4, 8 and 12 weeks) o...

The hypothesis that the changes in vascular reactivity seen during pregnancy are determined by the gestational age was examined. Experiments were designed to investigate changes in vascular responses with progression of pregnancy. The contractile responses to potassium and phenylephrine (in the presence and absence of N(omega)-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor) an...

The actin cytoskeleton of adherent tissue cells often condenses into filament bundles contracted by myosin motors, so-called stress fibers, which play a crucial role in the mechanical interaction of cells with their environment. Stress fibers are usually attached to their environment at the endpoints, but possibly also along their whole length. We introduce a theoretical model for such contract...