Ukurasa 1 kutoka 32 matokeo
Flow-mediated vasodilation is endothelium dependent. We hypothesized that flow activates a potassium channel on the endothelium, and that activation of this channel leads to the release of the endogenous nitrovasodilator, nitric oxide. To test this hypothesis, rabbit iliac arteries were perfused at
1. In vitro studies were undertaken to investigate the effects of external potassium ([K+]o) and magnesium ([Mg2+]o) concentration on canine coronary arterial basal tone and on 5-hydroxytryptamine (5-HT)-induced contractions. 2. Acute withdrawal of, or reduction in, [K+]o produced relaxation of
The umbilical arteries play an important role in the foetal circulation. These vessels, which have no sympathetic tone, are a valuable model for the study of a direct pharmacological effect on vascular smooth muscle. The aims of this study were to determine if the potassium-channel reopener,
1. Vascular contractions induced by K(+)-free solution and relaxation responses following the return of K+ to the organ bath were studied in mesenteric arterial rings from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) with particular focus on the role of vascular
High-potassium cold storage solutions are currently used to preserve myocardial function during heart transplantation. However, the effects of high potassium concentration on vascular endothelial function are not well known. We therefore tested vascular rings for endothelial-dependent and
Background/objectives: Hibiscus sabdariffa L. (H. sabdariffa (HS)) extract has a vascular relaxant effect on isolated rat thoracic aorta, but data on small resistance arteries, which play an important role on
K+ channels play a key role in regulation of membrane potential and cell excitability. Several different types of K+ channels have been identified and the presence, characteristics and functions of these channels vary among different tissues. The 3 most important K+ channels in smooth muscle are the
OBJECTIVE
N-acetylcysteine (NAC) has a protective effect against vascular dysfunction by decreasing the level of reactive oxygen species (ROS) in experimental and human hypertension. This study was designed to examine whether NAC would relax vascular rings in vitro via nitric oxide-cyclic guanosine
Previous in vivo studies have shown that vasopressin, which releases the endothelium-derived relaxing factor and constricts coronary smooth muscle, produces augmented constriction of coronary microvessels perfused by mature collaterals. We hypothesized that chronic perfusion through collaterals
This study was conducted to investigate whether the novel orally active nonpeptide angiotensin II (Ang II) AT(1) receptor antagonist irbesartan interacts with the thromboxane A(2)/prostaglandin endoperoxide H(2) (TxA(2)/PGH(2)) receptor in canine coronary arteries and human platelets. Coronary
Propofol is an intravenous anesthetic that can be used for the induction and maintenance of anesthesia. In the present study, it was aimed to investigate the mechanism of vasodilator action of propofol in the rat aorta (RA).METHODS
The RA rings were
The contraction/relaxation responses of thoracic aortal rings clamped with two clamping pressures to potassium chloride (KC1), noradrenaline and carbachol were studied using a scanning electron microscope (SEM) to ascertain endothelial lacerations. Clamp A had the tip pressure PA = 0.60 N/mm2 and
The inhibitory and relaxing effects of prazosin, nifedipine, and dihydralazine on contractions induced by noradrenaline (NA), or potassium (K+), were investigated in isolated human crural and mesenteric arteries and veins. Vascular ring preparations were suspended in organ baths and isometric
The purpose of this study was to determine the physiologic effects of cigarette smoke exposure and dietary cholesterol on the availability of nitric oxide in carotid vascular rings. New Zealand white rabbits were placed in an airflow chamber for 3 hr/day over an 8-week period and were exposed to
We tested the hypothesis that products released from contracting skeletal muscle could induce the release of vasodilatory products from vascular endothelium. Superfused endothelium-denuded rabbit aortic and dog femoral artery rings contracted with 1 microM phenylephrine delivered at 1-2 mL/min were