Effect of endothelin on the canine basilar artery

Endothelin, a recently discovered peptide produced by endothelial cells, has been shown to have potent constrictor effects on major arteries in vitro. This experiment was performed to determine whether endothelin plays a physiological role in cerebral vasospasm after subarachnoid hemorrhage. A cisternal injection of endothelin (10(-8) mol or 10(-9) mol) caused severe vasoconstriction of the canine basilar artery. The degree of vasoconstriction was dose related and long lasting, persisting for more than 24 hours. This constriction was prevented completely by pretreatment with nicardipine (10(-8) mol). Endothelin produced a marked and transient elevation in blood pressure and might play an important role in cerebral vasospasm. Further investigation will be needed to determine the role of endothelin in the pathogenesis of vasospasm.