Fig. 2. Effects of 8Br-cADPR and ADP-ribosyl cyclase inhibitors on ACh-induced Ca²⁺ oscillations. (A) Typical ACh-induced Ca²⁺ response obtained in a myocyte permeabilized with 10 µg/ml saponin in control conditions and in the presence of 20 µM 8Br-cADPR for 5 minutes. (B) Compiled data showing the effects of 8Br-cADPR (20 µM) in presence of 10 nM 4DAMP for 5 minutes on the amplitude of the first Ca²⁺ peak of ACh-induced Ca²⁺ responses (left) and on the percentage of oscillating permeabilized cells (right). (C) Compiled data showing the effects of ZnCl₂ (2 mM, 5 minutes) or NGD+ (2 mM, 15 minutes) on the amplitude of the first Ca²⁺ peak of ACh-induced Ca²⁺ responses (left) and the percentage of oscillating permeabilized cells (right). (D) Compiled data showing the effects of an anti-CD38 antibody (1 µg/ml, 5 minutes) on the amplitude of ACh-induced Ca²⁺ responses (left) and the percentage of oscillating permeabilized cells. Cells were permeabilized with 100 µg/ml saponin. The inactivated antibody was obtained by heating (90°C, 20 minutes). Data are means ± s.e.m. with the number of tested cells indicated in parentheses. Myocytes were loaded with 2 µM Fluo4-AM (stars indicate P<0.05).