Prostaglandin metabolism in experimental cerebral vasospasm

Abstract
Experimental cerebral vasospasm was produced in the canine basilar artery by an intracisternal injection of fresh autogenous arterial blood. Prostaglandins generated in spastic and nonspastic arteries were assessed by TLC. Prostaglandins synthesized in normal arteries were 6-keto-prostaglandin (PG)F1.alpha., PGF2.alpha., PGE2 and PGD2; 6-keto-PGF1.alpha. was the most abundant prostaglandin. The study of platelet aggregation suggested that prostacyclin (PGI2)-like activity was manufactured by the normal basilar artery. At 5 min after the intracisternal blood injection, no significant changes were evident in syntheses of prostaglandins generated by spastic artery. PGE2 synthesis was significantly increased in spastic artery 2 days after the intracisternal blood injection and 6-keto-PGF1.alpha. and PGF2.alpha. synthesis and PGE2 synthesis were significantly decreased and increased, respectively, in spastic artery 6 days after the intracisternal blood injection. No significant changes were found in syntheses of 6-keto-PGF1.alpha., PGF2.alpha. and PGE2 manufactured by nonspastic arteries at any stage. Formation of thromboxane B2 was not detected in normal, spastic or nonspastic arteries.