Plasma endothelin concentrations in hypertension

The endothelins comprise a family of potent vasoconstricting peptides. Endo thelin-l appears to be the predominant isoform produced by the vascular end othelium, acting mainly in a paracrine fashion on vascular smooth muscle ce lls to cause vasoconstriction. It also has a range of other local actions - in the kidney, in the nervous system and on other hormone systems - that c ould, potentially, play a part in the genesis of hypertension. The associat ion of raised plasma endothelin concentrations in human hypertension has ca used much interest, but the literature is not consistent. Given the general ly low plasma concentration of the endothelins, and their mainly paracrine actions, it remains unclear whether plasma endothelin has a functional role in hypertension. Additionally, problems remain with the measurement of pla sma endothelin that raise doubts about the validity of conclusions drawn fr om these measurements.