Fig. 4.

Intracellular Ca²⁺ transient in TG and WT cardiomyocytes. A: representative fura-2 AM fluorescence (the ratio of 360-to-380 nm-excited emission at 510 nm) traces of intracellular Ca²⁺ transient in TG and WT cardiomyocytes at baseline and under ISO treatment. B: quantitative analysis showed no difference in the levels of resting Ca²⁺ between TG and WT cardiomyocytes. Treatment with ISO did not result in significant change in resting Ca²⁺. Peak intracellular Ca²⁺ transient was also similar in the TG and WT cardiomyocytes and isoproterenol treatment increased peak Ca²⁺ transient in both groups (+P < 0.05, ++P < 0.01).