Figure 1.

Perfusion of intact ventricular cardiomyocytes with a high concentration (30 µM) of IpTxa causes immediate cessation of [Ca²⁺]_i transients. (A) line-scan image (top) and associated fluorescence plot (bottom) of a field-stimulated mouse ventricular cardiomyocyte loaded with the Ca²⁺ indicator Fluo-4 and perfused constantly with normal Tyrodes solution in the absence of IpTxa (control). (B) The same cell ~1 min after perfusion with the same Tyrodes solution, but containing 30 µM IpTxa. The protocol was repeated four times and the result below is representative of three experiments.