Fig. 4

Selective Ca²⁺ elevation in female myocytes at end ischemia is abrogated with hypertrophy. a Representative cardiomyocyte shortening record shows modulated diastolic length and twitch amplitude in simulated ischemia and reperfusion (time compressed). b All groups show a similar pattern of shortening response to simulated ischemia. c No significant difference between groups was detected in the extent of change in twitch reduction at end ischemia. d Ca²⁺ transient responses during the time-course of simulated ischemia. e Female NHR cardiomyocytes exhibited a substantial increase in amplitude Ca²⁺ at the end of ischemia which was not evident in female hypertrophic myocytes. f Diastolic Ca²⁺ increased throughout ischemia in male HHR cardiomyoctes. g At end ischemia, increased diastolic Ca²⁺ in male HHR was absent in female HHR myocytes. (*sex p < 0.05; #strain p < 0.05; †sex-strain interaction; §post hoc male vs female p < 0.05; mean ± SEM; n = 7–14 cells from 6 to 11 hearts/group)