Absence of elevation of big endothelin in subarachnoid hemorrhage.

BACKGROUND AND PURPOSE

Endothelin peptides are potent vasoconstrictors and thus are seen as potential cause of cerebral vasospasm after subarachnoid hemorrhage (SAH). Earlier reports showed elevated or normal endothelin levels in plasma and cerebrospinal fluid in patients suffering from SAH. The present study was designed to determine whether endothelin is a causal factor in SAH.

METHODS

We studied 11 patients with acute SAH. Seven of these 11 patients had a proven aneurysm and six had experienced vasospasm. Big endothelin levels were determined by a radioimmunoassay recognizing the C-terminal peptide (normal range, 1-11 fmol/ml).

RESULTS

There were no elevations of big endothelin in the 59 plasma samples and the 17 simultaneously estimated cerebrospinal fluid samples. Differences between plasma and cerebrospinal fluid did not reach significant levels. Big endothelin values between patients with and without vasospasm showed no significant differences.

CONCLUSIONS

Our findings suggest that plasma elevation of the endothelins is not reproducible in SAH and that big endothelin is unlikely to be a causal plasma factor in the complex multifactorial development of vasospasm after SAH.