Effects of nicotine on action potentials of guinea pig and rabbit papillary muscles
Abstract
The electrophysiological action of nicotine was studied by microelectrode technique on isolated guinea pig and rabbit papillary muscles. Nicotine had no significant effect on RP, APA and Vmax; but its biphasic effect on APD35, APD90 and ERP were observed in different concentrations, ie: high concentration (604 mumols/L) prolonged APD35, APD90 and ERP by 27.3, 26.0 and 26.1% respectively, whereas low concentration (0.6 mumol/L) shortened them by 49.6, 40.0 and 27.6%, respectively. It is suggested that high concentration of nicotine may enhance the calcium influx, but low concentration decrease it.
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