Fig 4.

Intracellular Ca²⁺ properties of cardiomyocytes from male young and old FVB and catalase (CAT) mice. A: Baseline intracellular Ca²⁺ levels (360/380 ratio); B: Rise in intracellular Ca²⁺ levels in response to electrical stimulus (360/380 ratio); C: First exponential decay constant of intracellular Ca²⁺; and D: Bi-exponential decay constant of intracellular Ca²⁺. Mean ± SEM, n = 43 cells from 5 mice per group, * p < 0.05 vs. FVB-young group, # p < 0.05 vs. FVB-old group.