Endothelium-derived relaxing factors (EDRFs), including nitric oxide (NO), prostacyclin (PGI2), and endothelium-derived hyperpolarizing factor (EDHF), play pivotal roles in regulating vascular tone. Reduced EDRFs cause impaired endothelium-dependent vasorelaxation, or endothelial dysfunction. Impaired endothelium-dependent vasorelaxation in response to acetylcholine (ACh) is consistently observ...

The role of endothelial calcium signaling in exercise-enhanced ACh-induced vasorelaxation was examined using male Wistar rats (8~10 wk old) that were divided into control and exercise groups. The exercised animals ran on a treadmill with progressive increments of speed until exhaustion. After decapitation, aortic rings were dissected and loaded with fura 2-AM. After being mounted on a tissue fl...

The endocannabinoid anandamide (AEA) causes vasorelaxation in animal studies. Although circulating AEA levels are increased in many pathologies, little is known about its vascular effects in humans. The aim of this work was to characterise the effects of AEA in human arteries. Ethical approval was granted to obtain mesenteric arteries from patients (n=31) undergoing bowel resection. Wire myogra...

BACKGROUND Impaired beta-adrenergic receptor (AR)-mediated vasorelaxation in hypertension plays a role in increased peripheral vascular resistance and blood pressure. Because the beta(2)AR is the most abundant vascular AR subtype, we sought to enhance betaAR vasorelaxation by overexpressing beta(2)ARs via adenoviral-mediated gene transfer (ADbeta(2)AR) to the vascular endothelium of the carotid...

The dynamic adjustment and amplitude of the endothelium-dependent vasorelaxation of the carotid, aorta, iliac, and femoral vessels were measured in response to acute low- (LI) or high-intensity (HI) endurance exercise. Vasorelaxation to 10(-4) M ACh was evaluated in 10 control, 10 LI, and 10 HI rats. Two-millimeter sections of carotid, aorta, iliac, and femoral arteries were mounted onto a myog...

Various laboratories have reported that local subcutaneous or subdermal injection of VEGF(165) at the time of surgery effectively attenuated ischemic necrosis in rat skin flaps, but the mechanism was not studied and enhanced angiogenesis was implicated. In the present study, we used the clinically relevant isolated perfused 6 x 16-cm pig buttock skin flap model to 1) test our hypothesis that VE...

The aim of the present study was to examine whether endocannabinoids cause PPARγ-mediated vascular actions. Functional vascular studies were carried out in rat aortae. Anandamide and N-arachidonoyl-dopamine (NADA), but not palmitoylethanolamide, caused significant vasorelaxation over time (2 hours). Vasorelaxation to NADA, but not anandamide, was inhibited by CB(1) receptor antagonism (AM251, 1...

objective(s) diabetes related dysfunction of resistance vessels is associated with vascular occlusive diseases. vasorelaxant agents may have a role in control of diabetic cardiovascular complications. gamma aminobutyric acid (gaba) has demonstrated to cause vasorelaxation. the present study was designed to determine i) the vasorelaxatory effect of gaba on diabetic vessels and ii) the role of en...

l-Arginine supplementation has been shown to restore endothelium-derived nitric oxide production in several pathological states. The purpose of this study was to examine the effect of administration of exogenousl-arginine on the endotoxin-induced lung neutrophil accumulation and impairment of endothelium-dependent guanosine 3',5'-cyclic monophosphate (cGMP)-mediated pulmonary vasorelaxation in ...

Endotoxin (Etx) causes excessive activation of the nuclear repair enzyme poly(ADP-ribose) synthase (PARS), which depletes cellular energy stores and leads to vascular dysfunction. We hypothesized that PARS inhibition would attenuate injury to mechanisms of pulmonary vasorelaxation in acute lung injury. The purpose of this study was to determine the effect of in vivo PARS inhibition on Etx-induc...