Figure 1.

[Ca²⁺]_i transients in HEK-293 cells in response to epidermal growth factor, the muscarinic agonist CCh and the purinergic agonist ATP, as seen in the continuous presence of extracellular Ca²⁺. (A) Averaged changes in [Ca²⁺]_i, observed in 11 cells. (B) Records of changes in two individual cells of the set. Additions and washouts of the agonists are depicted by the gray areas and the black bars at the top. For details see of [Ca²⁺]_i determination see Zhu et al. (6).