Trimedazidine Alleviates Pulmonary Artery Banding-Induced Acute Right Heart Dysfunction And Activates Pras40 In Rats

The molecular mechanism underlying acute right heart failure (RHF) is poorly understood. We used pulmonary artery banding (PAB) to induce acute RHF characterized by a rapid rise of right ventricular pressure, and then a decrease in right ventricular pressure along with a decrease in blood pressure right after banding. We found higher brain natriuretic peptide (BNP) and beta-myosin heavy chain (beta MHC) levels and lower alpha-myosin heavy chain (alpha MHC) levels in RHF rats than shamoperated rats. Hemodynamic indexes in rats with acute RHF were slightly improved by trimedazidine TMZ, a key inhibitor of fatty acid (FA) oxidation. TMZ also reversed downregulation of peroxisome proliferator-activated receptor gamma coactivator 1-beta (PGC-1 beta) and peroxisome proliferator-activated receptor alpha (PPAR alpha) by PAB and up-regulates peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1 alpha), peroxisome proliferator-activated receptor delta (PPAR delta) and pyruvate dehydrogenase kinase isoform 4 (PDK4). In addition, TMZ reversed upregulation of phosphorylated Akt by PAB and increased phosphorylated prolinerich Akt-substrate 40 (PRAS40). Autophagy and apoptosis were not modified by PAB or TMZ. An acute RHF model was established in rats through 70% constriction of the pulmonary artery. TMZ treatment alleviated PAB-induced acute RHF by activating PRAS40 and upregulatingPGC-1 alpha, PGC-1 beta, PPAR alpha, PPAR delta, and PDK4.