**5.3. Non-energy producing mitochondrial mechanisms of right heart failure**

Studies of non-energy producing roles of mitochondria are in their infancy in the RV. However, some evidence supports a causative role of ROS, as increased lipid peroxidation is observed in the RV 6 weeks following MCT injection [98]. NADPH oxidase is significant source of ROS in LV hypertrophy, and its expression increases during MCT-induced RV hypertrophy alongside decreased SOD1 and SOD2 expression [99]. Increased expression of pro-apoptotic proteins Bax and capase-3 have also been noted in the RV after PAB, with concomitant increased RV myocyte cell death [100]. Together, the limited investigations of the metabolic and nonmetabolic roles of mitochondria in right heart failure highlight the need for additional work to elucidate similarly and differentially regulated pathways in left and right HF.
