Figure 4.

Slowed kinetics of sarcomere shortening in the ZSF1‐obese group. A and B, Recordings of the steady‐state changes in sarcomere length at 0.1 and 4 Hz, respectively, in ZSF1‐lean (black, left y‐axes) and ZSF1‐obese (red, right y‐axes). C and D, Similar diastolic sarcomere length and sarcomere shortening as a function of stimulation frequency in ZSF1‐lean and ZSF1‐obese. E and F, Slowing of both the rise time and the decay half‐time of sarcomere shortening. The recordings in A and B were obtained from the same cells as shown in Figure 1. G, Half‐width is significantly higher in ZSF1‐obese than ZSF1‐lean but this difference was attenuated with the increases of frequency. The average values (±SEM) at 0.1, 1, 2 and 4 Hz were obtained from 70, 47, 35 and 22 different cells in ZSF1‐lean and from 112, 62, 45 and 29 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