Fig. 4.

A: activated caspase-3 staining in Purkinje fibers calculated as number of positive-stained nuclei per Purkinje fiber area; groups are as indicated in Fig. 1. Data are expressed as means ± SE. *Significantly different from control. B: activated caspase-3 staining in Purkinje cells in fetal hearts showed a distribution pattern depending on the location within the ventricular free walls or septum. Activation of caspase-3 in Purkinje fibers was greater in the subendocardial spaces of septum (SL, SR) and left ventricle (LV) than in the right ventricular free wall (RV), although the apoptosis in the septum on the side adjoining the LV chamber was greater than that in the LV free wall adjoining the same chamber.