Figure 2.

Ca²⁺ influx through L-type Ca²⁺ channels was not involved in the positive inotropic effect of troglitazone. (A) The positive inotropic effect of troglitazone was not inhibited by pretreatment with verapamil in perfused rat hearts (n=5, respectively). (B) Representative time course of peak inward L-type Ca²⁺ current in ventricular myocytes before and during perfusion of troglitazone (50 μM). (C) Original current traces recorded at −20, 0, and 20 mV in the absence and presence of troglitazone. (D) The summarized data for I–V relationships of the inward L-type Ca²⁺ current before and during in the presence of troglitazone (n=6, respectively). Note that troglitazone did not have any effect on the Ca²⁺ current in left ventricular myocytes. Changes of parameters are expressed as per cent changes from the baseline values (A). ^*P<0.05 vs vehicle.