Fig. 4
Effects of [K+]o on [Ca2+]i increase stimulated by 1 and 5 μM IM. a Effects of [K+]o on the rate of F340/F380 increase (Ca2+ influx). During 5 μM IM stimulation, the rate of [Ca2+]i increase linearly decreased. The intercept of the x axis was 4.5 M. During 1 μM IM and 4 μM TG stimulation, the rates of [Ca2+]i increase linearly decreased. The intercepts of the x axis were 144 mM during IM stimulation and 131 mM during TG stimulation. b Effects of [K+]o on the sustained F340/F380. With increasing [K+]o, the final [Ca2+]is are almost constant during 5 μM IM stimulation. However, with increasing [K+]o, the final [Ca2+]i linearly decreased