Fig. 5.

Effects of SERCA pump inhibition by cyclopiazonic acid (CPA) on the Ca²⁺ transients induced by brief (10 s) applications of CCh in Ca²⁺-free solution. (A) Ca²⁺ transients induced by a series of 10 s applications of CCh in Ca²⁺ free solution (control experiments); (B) inhibition of CCh-induced Ca²⁺ transients induced by CCh in Ca²⁺ free solution by CPA (20 μM). In these protocol EC were first pre-exposed to Ca²⁺-free solution with 2 mM EGTA for 3 min to fully remove external Ca²⁺.