RESUMEN
Objective To investigate the antagonism of third generation dihydropyridine calcium channel antagonist beni-dipine in contraction induced by potassium chloride(KCl)in human internal mammary artery(IMA),and in order to explore the possibility of using benidipine as an antispastic agent during coronary artery bypass grafting(CABG). Methods The IMAs were taken from 19 patients undergoing CABG. The vasodilator effect(n = 7)on KCl-induced contraction and the inhibition effect(n = 6)after incubation with benidipine were studied in a myograph. The caveolin 1. 2 was detected(n = 3,2 cases re-spectively)by enzyme-linked immunosorbent assay (ELISA). Results The maximum relaxation caused benidipine was (87. 7 ± 4. 9)％ . Incubation with benidipine significantly depressed the contraction by KCl[from( 16. 9 ± 4. 4)mN to (9. 1 ± 3. 4 )mN,P < 0. 01]. The concentration of caveolin 1. 2 was down-regulated after incubation with benidipine(P < 0. 05). Conclusion Benidipine has a potent inhibitory effect on KCl-induced vasoconstriction. The relaxation may be related with the expression of caveolin 1. 2. Using benidipine in patients undergoing CABG may provide antispastic effects in grafts.