HMOX1 and Right ventricular hypertrophy: In contrast, the dietary supplement Protandim, which increases expression of antioxidant enzymes such as SOD and heme-oxygenase-1, neither reduced RVSP nor pulmonary vascular remodeling in chronic hypoxia/SU5416-treated rats, but prevented right ventricular hypertrophy and preserved right ventricular function [18].