Figure 5.

Time course of Ca²⁺ influx in rabbit platelets in the presence (solid line) and absence (dotted line) of external 5 mM K⁺ with (•) and without (○) ouabain. Platelets were incubated for 40 min at 37°C in Ca-free Tyrode-HEPES albumin buffer with or without 0.1 mM ouabain. The graph shows a typical experiment from four experiments with duplicate or triplicate determinations.