TY - JOUR T1 - Actions of phencyclidine on the action potential and membrane currents of single guinea-pig myocytes. JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 131 LP - 136 VL - 237 IS - 1 AU - R W Hadley AU - J R Hume Y1 - 1986/04/01 UR - http://jpet.aspetjournals.org/content/237/1/131.abstract N2 - The direct actions of phencyclidine (PCP) on mammalian sarcolemma were examined by determination of the drug's effects on the action potentials of isolated guinea-pig ventricular cells, and on the underlying ionic currents. PCP (10(-6) to 10(-4) M) did not alter the resting membrane potential but produced a dose-dependent prolongation of the duration of the action potential, and a reduction of the rate of depolarization of phase 0 (Vmax) of the action potential. Voltage clamp experiments revealed that PCP blocks both myocardial Ca++ channels and myocardial time-dependent K+ channels. The K+ channel blockade was shown to exhibit an apparent voltage-dependence. The effects of PCP on these ionic channels could explain previous reports of it prolonging myocardial action potentials and conflicting reports of positive and negative inotropism. ER -