Figure 1. Effects of Ins(1,3,6)P₃ on Ca²⁺ inflow and the vasopressin-induced increase in [Ca²⁺]_cyt in single rat hepatocytes.

Single hepatocytes were injected with fura 2 plus 220 μM Ins(1,3,6)P₃ (estimated intracellular concentration) (A) or fura 2 alone (B) 10 min before beginning the measurement of fluorescence. Additions of Ca²⁺ (1.5 mM) and vasopressin (40 nM) were made as indicated by the horizontal bars. Each trace is representative of those obtained for 21–97 individual cells from two to seven separate hepatocyte preparations.