Fig. 4.
Progressive electrophysiological changes following superfusion with Tyrode solution containing 12 mM [K+]o (BCL= 800 ms). A: Endo and Epi APs recorded from isolated RV tissue slices using the standard microelectrode technique. Vmax traces are shown underneath the respective APs. Consecutive sets of recordings were obtained at 5-mV depolarization intervals between the resting membrane potentials (RMPs) of −86 and −66 mV. Right traces show 5 consecutive beats of Endo and Epi APs superimposed. B: Vmax as a function of membrane depolarization in Endo and Epi. Values are means ± SE; n = 9 Endo and 14 Epi. *P < 0.05 vs. RMP of −86 mV.