Jpn. J. Pharmacol. 83 (2), 107-112 (2000)
Electrophysiological and Cardiohemodynamic Effects of AH-1058, a New
Type Calcium Channel Blocker, Assessed by the In Vivo Canine Model
Akira Takahara1, Atsushi Sugiyama2,*, Hideki Dohmoto1,
Ryota Yoshimoto1 and Keitaro Hashimoto2
1PharmaceuticalÊResearch Laboratories, Ajinomoto Co., Inc.,
1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan
2DepartmentÊof Pharmacology, Yamanashi Medical University, Tamaho-cho,
Nakakoma-gun, Yamanashi 409-3898, Japan
*ÊTo whom correspondence should be addressed.
Abstract: AH-1058Ê(4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)-1-[(E)-3-(3-methoxy-2-nitro)phenyl-2-propenyl]piperidine
hydrochloride) is a novel calcium channel blocker whose chemical structure
is quite different from those of typical calcium channel blockers. In this
study, electrophysiological and hemodynamic effects of AH-1058 were assessed
in the halothane-anesthetized, closed-chest canine model. Intravenous administration
of a canine antiarrhythmic dose of 100Êmg/kg
of AH-1058 (n=6) did not affect the cardiovascular variables, except that
the cardiac output was decreased at 30Êmin after the drug administration.
Additional administration of 200Êmg/kg of AH-1058
(n=6) suppressed the sinus nodal automaticity, AV nodal conduction and ventricular
contraction and decreased the mean blood pressure, cardiac output and double
product. The effects gradually appeared, while no change was detected in
the intraventricular conduction, ventricular repolarization period, ventricular
effective refractory period, preload to the left ventricle and total peripheral
vascular resistance during the observation period of 30Êmin. The cardiosuppressive
effects of AH-1058 can be explained by its calcium channel blocking action
demonstrated in a previous in vitro experiment, while the lack of the effect
on the vascular resistance would suggest that AH-1058 may become a slow-acting
cardioselective calcium channel blocker.
Keywords: AH-1058, Calcium channel blocker, Electrophysiologic effect,
Hemodynamic action,
Monophasic action potential
Copyright© The Japanese Pharmacological Society 2000
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