Cell proliferation in the fetal ventricular myocardium. (A) Representative histological heart sections immunostained for pHH3. pHH3+ staining (brown) is localized in the nucleus. (B and C) Quantification of pHH3+ cells in heart tissue sections, which include the right, left and septal myocardium. Data are means ± SEM, n = 6–8 per group *P < 0.05 vs. untreated control, †P < 0.001 vs. untreated diabetes. Scale bar is 50 μm.