Fig. 4.

Influence of intracellular Ca²⁺ oscillations by extracellular Ca²⁺ concentration in single HEK293 cells. Typical traces represent the three main patterns of Ca²⁺ signal responses, sustained single Ca²⁺ rise (the upper panel), short lasting (the middle panel) and the typical Ca²⁺ transients (the bottom panel), to 5 μM Carb in 0.1 μM fura2 loaded cells incubated in the HBSS containing 1.8, 1.5 or 1.2 mM extracellular Ca²⁺ (3 groups) as indicated. These patterns of Ca²⁺ signals were found in the 3 groups of cells but with different occurrence proportion, which are further summarized in Table 1. Similar results were obtained from 58–216 cells in at least 16 independent experiments for all panels