Recovery of CARC after Stimulation.
(A) In one protoplast, Ca2+ was increased (left) in ramplike fashion, resulting in CARC. After 155 sec, this procedure was repeated (right). Both procedures caused CARC with large (first stimulation) and low (second stimulation) amplitude. In the inset, the CARCs from the first stimulation (line) and from the second stimulation (dots) are scaled to the same ordinate.
(B) Ratio of amplitudes from second (A2) and first (A1) CARC as a function of the time between stimulations. Amplitudes were measured at isochronal times after [Ca2+]cyt–stimulated ΔCm.