The contractile response to endothelin has been examined in cerebral arteries from rats subjected to a prior subarachnoid haemorrhage (SAH) and compared with saline injected controls. Endothelin elicited strong concentration-dependent contraction of rat basilar artery segments. The response was slow in onset and long lasting. The endothelin-induced contraction was much stronger in the SAH compared to control animals. Our findings suggest a role of the peptide in the pathophysiology of cerebral vasospasm
