Inhibitory effects of heparin, aspirin and ketanserin on coronary artery vasoconstriction after arterial balloon injury in hypercholesterolemic miniature pigs.

ABSTRACT

OBJECTIVES: The present study aimed to clarify the effects of heparin, aspirin and ketanserin on coronary artery vasoconstriction after arterial balloon injury. BACKGROUND: The mechanisms of coronary artery vasoconstriction after coronary angioplasty are not well understood. METHODS: After being fed a cholesterol-rich diet for 1 month, 71 Göttingen miniature pigs were randomly allotted to five groups 16 pigs with no pretreatment (group A); 21 pigs pretreated with heparin, 3,000 U (group B); 13 pigs pretreated with aspirin, 50 mg/day orally for 2 days (group C); 11 pigs pretreated with ketanserin, 1 mg/kg body weight (group D); 10 pigs pretreated with aspirin, 50 mg/day for 2 days, heparin, 6,000 U and ketanserin, 1 mg/kg (group E). After this pretreatment, the left anterior descending or the left circumflex coronary artery, or both, was denuded by a 2F balloon catheter. RESULTS: The coronary vasoconstriction at the injured sites reached a peak level 6 min after the arterial injury and subsided within 30 min. The coronary vasoconstriction at the injured site 6 min after arterial injury was 56 +/- 5% in group A, which was significantly greater than that in group B (28 +/- 6%, p < 0.01), group C (25 +/- 5%, p < 0.01), group D (26 +/- 7%, p < 0.01) or group E (24 +/- 5%, p < 0.01), whereas there was no significant difference in the coronary vasoconstriction among the latter four groups. CONCLUSION: These results suggest that serotonin released from aggregating platelets plays a major part in the platelet-dependent coronary artery vasoconstriction after arterial injury.