CAT and pulmonary arterial hypertension: With a progression of from RV hypertrophy to failure, down-regulation of antioxidant enzymes, and increased ROS production occurs in a mice model of pulmonary hypertension (Aziz et al., 2015; Reddy and Bernstein, 2015), although in one model of monocrotaline-induced RV failure, glutathione peroxidase increases while catalase, and SOD activities are similar to sham animals (Türck et al., 2018).