EFFECTS OF NIMODIPINE, FELODIPINE, AND VE RAPAMIL ON ISOLATED HUMAN ARTERIES

AIM: To evaluate whether there might be some difference in the action modes of nimodipine (Nim) and felodipine (Fel). METHODS: Compare the i nhibitory effects of Nim and Fel with that of verapamil (Ver) as a rep resentative of phenylalklamine on norepinephrine (NE)- and CaCl2-evoke d contractions of human arteries. RESULTS: In Ca2+- free and high K+ d epolarized solution, inhibitory effects of Nim, Fel, and Ver were more potent on CaCl2-induced contractions on isolated human arteries than those on NE-induced contractions. In CaCl2-induced contraction, the pD (2) values for Nim, Fel, and Ver were 7. 5, 7. 42, 6. 35 on uterine ar teries; 7. 38, 7. 65, 7. 20 on mesenteric arteries and 7. 87, 9. 10, 7 . 32 on renal arteries , respectively. Ver inhibited 2 components of N E-evoked contraction, while Nim and Fel only inhibited extracellular C a2+-dependent contractions. CONCLUSION: The result indicates that Fel has a selective action on human renal arteries.