5-AZA blocks dexamethasone (DEX)-induced effects on cardiomyocyte proliferation and binucleation in neonatal rats.

<p>Newborn rats were treated with tapered dose of DEX in the absence or presence of 5-AZA during the first three days of postnatal life. 5-AZA was administered 30 minutes prior to the DEX treatment. Panel <b>A</b>: Cardiomyocytes isolated from day 4 (P4) and day 7 (P7) neonatal hearts were double stained with α-actinin and Ki67, nuclei were stained with Hoechst. Panel <b>B</b>: Cardiomyocytes isolated from P7 neonatal hearts were examined for BrdU incorporation. Panel <b>C</b>: Cardiomyocytes isolated from P4 and P7 neonatal hearts were stained with α-actinin and Hoechst, and mononucleated and binucleated cells were determined. Data are mean ± SEM, n = 4–14. * p<0.05, DEX <i>vs</i>. Saline; # p<0.05, +5-AZA <i>vs</i>. -5-AZA; † p<0.05, P7 <i>vs</i>. P4.