We studied whether there is a quantitative relationship between free cytosolic Ca++ levels and the release of an endothelium-derived relaxing factor (EDRF) from cultured fetal bovine aortic endothelial cells (EC). EC pretreated with indomethacin were stimulated by the agonists adenosine triphosphate (ATP), bradykinin (BKN), acetylcholine (ACh) and calcium ionophore (A23187) in various concentra...

Background and Purpose The goal of this study was to determine whether release of endothelium-derived relaxing factor (EDRF) from carotid artery in response to acetylcholine is altered by aging. Methods Responses were examined in arteries from Wistar rats 6 to 8 months old (young rats), 24 to 26 months old (old rats), and 30 to 32 months old (very old rats). We used a bioassay technique to meas...

Endothelium-derived relaxing factor has been recently identified as nitric oxide. The purpose of this study was to determine if vasodilator drugs that generate nitric oxide inhibit vascular smooth muscle mitogenesis and proliferation in culture. Three chemically dissimilar vasodilators, sodium nitroprusside, S-nitroso-N-acetylpenicillamine and isosorbide dinitrate, dose-dependently inhibited se...

BACKGROUND Pulmonary hypertension is a hallmark of high-altitude pulmonary edema and may contribute to its pathogenesis. When administered by inhalation, nitric oxide, an endothelium-derived relaxing factor, attenuates the pulmonary vasoconstriction produced by short-term hypoxia. METHODS We studied the effects of inhaled nitric oxide on pulmonary-artery pressure and arterial oxygenation in 1...

The presence of a healthy epithelium can moderate the contraction of the underlying airway smooth muscle. This is, in part, because epithelial cells generate inhibitory messages, whether diffusible substances, electrophysiological signals, or both. The epithelium-dependent inhibitory effect can be tonic (basal), synergistic, or evoked. Rather than a unique epithelium-derived relaxing factor (Ep...

Nitrates are still widely used in the management of coronary artery disease (CAD) in patients with stable and unstable angina, acute myocardial infarction and congestive heart failure. The therapeutic efficacy of these nitrates is due to peripheral venous and arterial dilation that results in decreased myocardial oxygen consumption. Nitrates also dilate large coronary arteries and collaterals w...

Pulmonary hypertension is seen in patients in whom there is an increased pulmonary pressure (systolic pulmonary/ systemic arterial pressure > 60%; > 15–20 mm Hg). The disease slowly progresses, applying stress on the right heart function leading to heart failure and death. Although the precise mechanism of development of precapillary pulmonary hypertension remains to be defined, understanding o...

Intravital microscopy was used to study the effect of endothelium-derived relaxing factor (EDRF) on microvascular adrenoceptor sensitivity in rat cremaster skeletal muscle. NG-Monomethyl L-arginine (L-NMMA, 1-300 ,uM), an inhibitor ofEDRF formation, produced concentration-dependent constriction of arterioles and venules. When an intermediate amount of a-l versus a2-adrenoceptor tone was first p...