Inhibitory effect of lomerizine, a prophylactic drug for migraines, on serotonin-induced contraction of the basilar artery.
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 Ca(2+) release in 5-HT(2A)-expressing HEK293 cells. Moreover, neither antagonist affected ATP-induced Ca(2+) release. These results suggest that lomerizine may inhibit not only voltage-dependent Ca(2+) channels but also 5-HT(2A) receptors and so inhibit 5-HT-induced contraction in the basilar artery.
Department of Pathophysiology, School of Pharmacy, Showa University, Tokyo, Japan. masakazu@pharm.showa-u.ac.jp
Masakazu
M
Ishii
Shunsuke
S
Kobayashi
Masamichi
M
Ohkura
Ryuichi
R
Yamamoto
Shunichi
S
Shimizu
Yuji
Y
Kiuchi
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects* / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D008297:Male; D008881:Migraine Disorders / Q000517:prevention & control*; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*
D002121:Calcium Channel Blockers; D010879:Piperazines; D012701:Serotonin; C052424:lomerizine