Figure 3.

Enhanced levels of mitochondrial Ca²⁺ but similar frequency‐dependent kinetics of mitochondrial Ca²⁺ handling in the ZSF1‐obese group. A, The baseline values before the onset of stimulation were significantly larger in ZSF1‐obese in comparison to ZSF1‐lean. B and C, The end‐diastolic and peak systolic mitochondrial Ca²⁺ concentrations during stimulation were frequency‐dependent and significantly larger in ZSF1‐obese than in ZSF1‐lean. D, The amplitude of the beat‐to‐beat changes in mitochondrial Ca²⁺ concentration was frequency‐dependent and was significantly larger in ZSF1‐obese than in ZSF1‐lean. E, The speed of mitochondrial Ca²⁺ uptake was frequency‐dependent. The rise time of [Ca²⁺]_m at low stimulation frequency in ZSF1‐obese was significantly larger than in ZSF1‐lean, but the values converged at 4 Hz. F, The speed of mitochondrial Ca²⁺ release was frequency‐dependent, but the values in both groups were very similar. The average values (±SEM) at 0.1, 1, 2 and 4 Hz were obtained from 76, 49, 37 and 23 different cells in ZSF1‐lean and from 122, 63, 48 and 31 different cells in ZSF1‐obese respectively. *P < .05 vs ZSF1‐lean; #P < .05 vs 0.1 Hz (two‐way ANOVA). No significant interaction was observed between groups and stimulation frequency