Decreased capillary density and cardiac fibrosis in <i>Nkx2.5-Cre/Foxm1^fl/fl</i> heart.

<p>Microtome sections of paraffin-embedded hearts were prepared from either <i>Nkx2.5-Cre/Foxm1^fl/fl</i> or littermate control mice at P11 and stained for PECAM-1 (A–B), α-smooth muscle actin (αSM) (C–D) or Masson's Trichrome (E–H). Capillary density was decreased in <i>Nkx2.5-Cre/Foxm1^fl/fl</i> hearts at P11 (A–B, I), while coronary vessel formation was not altered (C–D). Numbers of capillaries were counted in PECAM-stained hearts using 10 random sections and mean±SEM was determined to confirm decreased capillary density (I). Significant fibrosis was detected in the IVS and ventricular walls of <i>Nkx2.5-Cre/Foxm1^fl/fl</i> hearts (F, H) while none was detected in control hearts (E, G). Significant differences (p<0.05) were indicated by asterisk. Scale bars represent 100 µm in A–F and 50 µm in G–H.