INCREASED PLASMA ENDOTHELIN-1 IN ACUTE ISCHEMIC STROKE

Background and Purpose: 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. Summary of Report. Plasma levels of endothelin-t 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<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. Conclusions: 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.