INHIBITORY EFFECTS OF NIMODIPINE ON PLATELET-AGGREGATION AND THROMBOSIS

AIM: To study the inhibitory effects of nimodipine (Nim) on rat platel et aggregation and arterial thrombosis in vivo. METHODS: The aggregati on rate of platelets induced by ADP and inhibition late of Nim were me asured by the change of light transmission, Effect of Nim on arterial occlusion time was measured by electric stimulation. Effect of Nim on the contents of 6-keto-PGF(1 alpha) and TXB2 in serum was measured by radioimmunoassay, RESULTS: Nim 4.5, 9, 18, and 36 mg . kg(-1) . d(-1) ig for 4 d restrained the; platelet aggregation, The IC50 (95% confide nce limits) was 26 (9-44) mg . kg(-1). Nim 4.5, 9, and 18 mg kg(-1) . d(-1) ig for 4 d markedly prolonged the time of thrombotic occlusion i n carotid artery induced by electric stimulation. Nim 9 and 18 mg . kg (-1) . d(-1) improved the imbalance of 6-keto -PGF(1 alpha)/TXB2 in se rum after thrombosis. CONCLUSION: Nim was a potent inhibitor of platel et aggregation, which was partially concerned with the improved balanc e of 6-keto-PGF(1 alpha)TXB(2).