Effects of ritanserin on transmembrane action potentials in canine Purkinje fibers.

Proc Soc Exp Biol Med

A.H. Robins Research Laboratory, Richmond, Virginia 23261.

Published: January 1992

Ritanserin has been reported to be a potential antiarrhythmic. We studied the cellular electrophysiologic effects of ritanserin in canine Purkinje fibers. Ritanserin produced significant depressant effects on transmembrane action potentials elicited in canine Purkinje fibers. At concentrations of 10 and 40 mg/liter, ritanserin decreased Vmax (the upstroke velocity) of action potential in a dose-dependent fashion and shortened the duration of fast response action potential. These concentrations of ritanserin also reduced the amplitude and duration of the slow response action potentials induced in Purkinje fibers treated with isoproterenol (10(-5) M) and high K+ (22 mM). These in vitro results suggest that the cellular electrophysiologic actions of ritanserin may be due to its direct actions on cardiac sodium and calcium channels, which, in turn, may account for its antiarrhythmic effects.

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http://dx.doi.org/10.3181/00379727-199-43334DOI Listing

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