L-arginine reduces right heart hypertrophy in hypoxia-induced pulmonary hypertension

Endothelin (Et) and nitric oxide (NO) may serve as chemical mediators of hypoxia-induced pulmonary hypertension. Plasma levels of Et1 were elevated 2-fold while levels of nitrate, a NO metabolite, decreased in rats exposed to 10 days of hypoxia (10% O2). Administration of l-arginine, the precursor for NO, decreased Et, increased nitrate, and decreased right ventricular hypertrophy in hypoxic animals. By increasing plasma NO levels, the right ventricular hypertrophy and right heart failure seen in hypoxia-induced pulmonary hypertension in human patients may be prevented.