Inhibitory Effect of Lomerizine, a Prophylactic Drug for Migraines, on Serotonin-Induced Contraction of the Basilar Artery

抄録

We examined the effects of lomerizine on serotonin (5-hydroxytryptamine, 5-HT)–induced contraction of the basilar artery and compared them with those of nifedipine. Although both lomerizine and nifedipine completely blocked K⁺-induced vasoconstriction, 5-HT–induced vasoconstriction was more strongly inhibited by lomerizine than nifedipine. A 5-HT_2A antagonist inhibited the 5-HT–induced vasoconstriction, but a 5-HT_1B antagonist did not. Lomerizine, but not nifedipine, suppressed 5-HT–induced Ca²⁺ release in 5-HT_2A–expressing HEK293 cells. Moreover, neither antagonist affected ATP-induced Ca²⁺ release. These results suggest that lomerizine may inhibit not only voltage-dependent Ca²⁺ channels but also 5-HT_2A receptors and so inhibit 5-HT–induced contraction in the basilar artery.