The arrival of oxygen in the active muscles can be impaired in animals with PAH (Marra et al., 2015), and this fact may explain the increased expression of PGC1-α in the animals from the EH group and not in those from the EM group, since the animals in the EH group were in a more critical stage of the disease. Here, PPARGC1A is linked to pulmonary arterial hypertension.