Age- and sex-specific differences in myocardial sympathetic tone and left ventricular remodeling following myocardial injury

Fig. 1. Myocardial sympathetic activity (MSA) assessed by [11C]mHED PET in male and female FVB/N mice after myocardial injury. A. Experimental design of the study with FVB/N mice subjected to 30 min ligation of the left anterior descending (LAD) artery, followed by a 24 h reperfusion period and subsequent PET imaging. B. Cardiac sympathetic nerve terminal and the suggested mechanism by which [11C]mHED is taken up via the norepinephrine reuptake transporter (NET) at sympathetic nerve terminals [19]. Abbreviations: [11C]mHED, [11C]meta-hydroxyephedrine; NE, norepinephrine; PET, positron emission tomography

Fig. 2. Infarct volume determined by cardiac magnetic resonance (CMR) imaging in FVB/N mice 24 h following myocardial injury. A. Young female vs. male animals at the age of 4–6 months, which were either gonadectomized (right) or sham operated (left). B. Old female vs. male animals at the age of 20–22 months, which were either gonadectomized (right) or sham operated (left). Representative late gadolinium enhancement (LGE) images showing the infarct area are depicted for the aged sham male (C) and aged sham female (D) heart. Infarct area is highlighted with white arrows. Abbreviations: ANOVA, analysis of variance; Gx, gonadectomized

Fig. 3. Left ventricular wall thickening and cardiac index assessed by cardiac magnetic resonance (CMR) imaging in FVB/N mice 24 h following myocardial injury. A. Left ventricular wall thickening in young and old female vs. male animals at the age of 4–6 and 20–22 months, respectively, which were either gonadectomized or sham operated, as indicated. B. Cardiac index in young and old female vs. male animals at the age of 4–6 and 20–22 months, respectively, which were either gonadectomized or sham operated, as indicated

Fig. 4. Myocardial sympathetic activity (MSA) assessed by [11C]mHED PET in an FVB/N mouse model of myocardial injury. A. Representative images of the mouse myocardium (highlighted by dashed line) 24 h following I/R injury and after intravenous [11C]mHED administration. B. Comparison of MSA at the anterior wall (infarct region) in young and old female and male animals that underwent gonadectomy (right) or sham surgery (left), respectively. C. Comparison of MSA at a remote region (non-infarct region) in young and old female and male animals that underwent gonadectomy (right) or sham surgery (left), respectively. Abbreviations: ANOVA, analysis of variance; Gx, gonadectomized; AU, arbitrary units

Fig. 5. Epinephrine levels obtained from urine sample analyses in FVB/N mice subjected to myocardial injury. A. Young female vs. male animals at the age of 4–6 months, which underwent either gonadectomy (right) or sham surgery (left). B. Old female vs. male animals at the age of 20–22 months, which underwent either gonadectomy (Gx, right) or sham surgery (left). Abbreviations: ANOVA, analysis of variance; Gx, gonadectomized