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Fig. 5 | Biology of Sex Differences

Fig. 5

From: Male and female hypertrophic rat cardiac myocyte functional responses to ischemic stress and β-adrenergic challenge are different

Fig. 5

Myofilament Ca2+ desensitization in hypertrophic male myocytes at the end of reperfusion is absent in females. a Cardiomyocyte survival plots throughout simulated ischemia and reperfusion. b Resting myocyte length decreased to a greater extent in male NHR cardiomyocytes compared with females, with this sex difference absent in the HHR. c At end reperfusion, male HHR cardiomyocytes maintain contractility yet exhibit significantly increased Ca2+. Female HHR myocytes show augmented contractility with substantially lower transient Ca2+. d Phase loop analysis shows male, but not female, HHR cardiomyocytes exhibit a modified Ca2+-shortening relationship. e Male HHR cardiomyocytes exhibit significantly lower level of myofilament Ca2+ sensitivity, with an approximate two to threefold increase in Ca2+ levels at 50 % myocyte relaxation. (*sex p < 0.05; #strain p < 0.05; †sex-strain interaction; §post hoc male vs female p < 0.05; mean ± SEM; n = 5–8 cells from four to six hearts/group)

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