Increased plasma endothelin-1 in acute ischemic stroke

Endothelin-1 exacerbates focal cerebral ischemia without exerting neurotoxic action in vitro

In a model of focal cerebral ischemia in mice, intracisternal injection of 5 and 10 pmol/mouse endothelin-1 significantly increased the infarcted surface area by 15.5% and by 23.5%, respectively. Endothelin-1 (0.01, 1, and 100 nmol/l) added to the primary neuronal cultures of chick embryo cerebral hemispheres for 1 h and 24 h did not influence the viability of the neurons or the protein content of the cultures. When applied simultaneously with 1 mmol/l sodium cyanide for 30 min, endothelin-1 (0.01, 1, and 100 nM) did not modify the hypoxia-induced changes. The results show that exogenously applied endothelin-1 could exacerbate cerebral ischemia, probably due to its vasoconstrictive properties and not to a direct neurotoxic effect.

Endothelins and sarafotoxins: physiological regulation, receptor subtypes and transmembrane signaling

The endothelins and sarafotoxins are two structurally related families of potent vasoactive peptides. Although the physiological functions of these peptides are not entirely clear, the endothelins are probably involved in pathophysiological conditions such as hypertension and heart failure. This review summarizes the state of the art in some areas of this intensively studied subject, including: (1) structure-function relationships of ET/SRTX, (2) ET concentrations in plasma, (3) ET/SRTX receptor subtypes and (4) signaling events mediated by the activation of ET/SRTX receptors.