Increased plasma endothelin-1 in acute ischemic stroke.

Endothelins are a recently discovered group of most powerful vasoconstrictor peptides. Endothelin-1 is produced by endothelial cells, and endothelin-3 is derived from neuronal tissue. Theoretically, endothelin-mediated vasoconstriction may enhance ischemic neuronal damage. This study aimed to measure plasma levels of both endothelins in patients with acute nonhemorrhagic cerebral infarction. Plasma levels of endothelin-1 and endothelin-3 were measured by radioimmunoassay in 16 consecutive patients within the first 72 hours after the onset of nonhemorrhagic cerebral infarct, as diagnosed clinically and by computed tomography. There was a marked (fourfold) elevation in plasma endothelin-1 levels in the patients (median, 11.7 pg/ml; 25th and 75th centiles, 5.4 and 13.2 pg/ml) compared with those in a control group of 13 age-matched subjects (median, 2.56 pg/ml; 25th and 75th centiles, 2.4 and 3.0 pg/ml; p less than 0.0001). The first 24 hours after stroke onset were associated with higher endothelin-1 levels, and there was a trend to elevated levels with more severe neurological deficits. In all patients and controls endothelin-3 levels were below 0.5 pg/ml. Ischemic stroke is associated with acute and marked increases in plasma levels of endothelin-1. This may reflect enhanced production by damaged endothelial cells within the infarcted tissue. Local leakage of endothelin-1 may induce severe and prolonged constriction of collateral vessels and may therefore have a deleterious role in the pathogenesis and final outcome of cerebral infarction.