Persistence of Cardiac Malprogramming in Late Gestational Fetal Sheep by Early to Mid-Gestational Testosterone Excess.

Excess testosterone (T) exposure from early to mid-gestation (days 30-90) leads to sexually dimorphic adverse cardiac left ventricular (LV) programming at fetal day 90 (term 147 days). Whether this sexually dimorphic impact is a direct effect of T or reprogramming that persists beyond early fetal life is unknown. We hypothesized that adverse sex-specific cardiac outcomes seen in early fetal life will persist in late gestational fetuses. Pregnant ewes received 100 mg T propionate intramuscularly twice weekly from gestational days (GD) 30 to 90 (term GD 147). At GD 120 ±5, impact of T treatment on left and right ventricles (LV and RV) weight and molecular markers were investigated in female control (FC), female T-treated (FT), male control (MC), male T-treated (MT) fetuses. Data was analyzed by two-way ANOVA and Cohen's effect size (d) analysis. Morphometrically, in the LV, T excess significantly increased percent ki67 positive cells, cyclin D1 gene expression as well as LV collagen and TUNEL staining in both sexes. Moreover, T excess impacted cardiomyocyte nucleation in a sexually dimorphic manner in the LV. Similar changes were not seen in the RV. At a molecular level, T excess significantly downregulated pAKT/Pan AKT and GLUT 4 protein selectively in LV suggestive of insulin resistance. These findings indicate a) persistence of the adverse organizational impact of prenatal T excess on the LV with evidence for cardiac insulin resistance in both sexes and b) differential impact of prenatal T excess on LV vs RV in late gestational fetuses.