Endothelin-1 (porcine/human) induced a prompt, reversible, potent, concentration-dependent contraction of bovine isolated retinal small arteries (internal diameter, approximately 200 microns) with a concentration of endothelin-1 required to give half-maximal contraction of 2 x 10(-10) M. The maximal contraction induced by endothelin-1 was equal to 89% of the maximal contractile capacity. The ve...

Endothelin-1 contracts vascular smooth muscle and inhibits release of neurotransmitter from adrenergic and cholinergic neurons. Experiments were designed to investigate the interaction of these mechanisms in a blood vessel that receives both adrenergic and cholinergic innervation. Rings cut from canine left anterior descending coronary arteries were suspended in organ chambers for the measureme...

Endothelins are peptides, originally isolated from endothelial cells, with potent vasoactive and mitogenic properties. In this study, we demonstrate that human macrophages synthesize and secrete endothelins. Cultured human macrophages were found by immunocytochemistry to stain positively for endothelin 1 and endothelin 3. Their capability to produce and release these peptides was confirmed by a...

Increased pulmonary vascular resistance in preterm newborn infants with respiratory distress syndrome is suggested, and endothelin-1 plays an important role in pulmonary vascular reactivity in newborns. We determined umbilical cord blood and neonatal (second sample) levels of endothelin-1 in 18 preterm newborns with respiratory distress syndrome who had no clinical or echocardiographic diagnosi...

OBJECTIVES The study evaluates the influence of treatment with the angiotensin-converting enzyme inhibitor, fosinopril, on the plasma endothelin level in patients with congestive heart failure, and the relationship between plasma endothelin and clinical study parameters (bicycle exercise test, echocardiography, heart failure score and blood pressure). METHODS Plasma endothelin was measured in...

Incubation with captopril, an angiotensin I converting enzyme inhibitor, for 24 hours at concentrations up to 10(-7) M inhibited endothelin-1 secretion by endothelial cells. This inhibition of endothelin-1 secretion was reversed by coincubation with 3 x 10(-3) M NG-nitro-L-arginine, an inhibitor of nitric oxide synthesis. Furthermore, captopril enhanced the production of nitric oxide in endothe...

The endothelin system has been implicated in the pathogenesis of acute liver failure. However, it has not yet been assessed in a tissue specific manner. - Acute liver failure was induced in rats by two intraperitoneal injections of galactosamine (1.3 g/kg, interval of 12 hours, n = 20). The animals were sacrificed after 48 hours. - Plasma measurements demonstrated that animals receiving galacto...

Endothelin, an endothelium-derived vasoconstrictor peptide, and angiotensin II were intravenously injected into the femoral vein of normotensive Wistar-Kyoto (WKY) rats that had been anesthetized with urethane. Blood pressure and heart rate were recorded from a cannula inserted into the carotid artery. All experiments were carried out after treatment with adrenergic and cholinergic antagonists....

BACKGROUND Based on recent evidence showing that endothelin-1 stimulates several activation mechanisms on neutrophils, the aim of the present study was to analyze the effects of endothelin-1 on neutrophil adhesion to endothelial cells and neutrophil accumulation in the heart. METHODS AND RESULTS The experiments included (1) adhesion of 51Cr-labeled human neutrophils to bovine endothelial cell...

The vasoactive peptide endothelin is shown to be a potent mitogen for Swiss 3T3 cells. Although endothelin has little effect on DNA synthesis when added alone to cells in serum-free medium, the peptide synergizes very strongly with several other growth factors. A half-maximal response to endothelin is observed at approx. 0.3 nM, with a maximal effect at 3 nM. Over the same concentration range, ...