DNM1L and pulmonary arterial hypertension: Similarly, Mdivi-1, a Drp1 inhibitor, rescued the mitochondrial fission and apoptosis resistance in PAECs isolated from PAH rats showing pulmonary plexiform-like lesions, which assessed via the quantification of the mean mitochondrial length (Fig. 5A-C), percent of fragmented mitochondria in cells (Fig. 5D-F) and apoptosis rate (Fig. 5G-I).