Effect of cocaine and cocaine metabolites on cerebral arteries in vitro.

Cocaine has pronounced peripheral vasoconstrictor effects. Despite the short half life of cocaine in the body these effects are relatively long-lived. The role of cocaine metabolites in vasoconstriction attributed to cocaine has not been reported. We evaluated the contractile ability of cocaine and its major metabolites in isolated cat cerebral arteries. The primary cocaine metabolite, benzoylecgonine was a potent contractile agent, causing a 50% decrease in cross sectional area at 10(-5) M. This was less than caused by serotonin, but greater than caused by norepinehrine. Ecgonine and cocaine were less active contractile agents than was benzoylecgonine, and ecgonine methyl ester was a mild relaxant.