Fig. 3.

Prolonged relaxation time of transgenic cardiomyocytes coexpressing fast TnT and cardiac TnT. Contractions paced at 2 Hz showed that time to half peak shortening (TP₅₀) was not significantly changed in the TG vs. the WT cardiomyocytes in the absence or presence of 30 nM ISO. However, time from peak shortening to 75% relengthening (TR₇₅) was significantly prolonged in the TG vs. WT cardiomyocytes (**P < 0.01). TR₇₅ was shortened by ISO treatment in both groups (++P < 0.01) but remained longer in the TG cardiomyocytes than the WT control (##P < 0.01).