Effects of Hypoxia and Inflammation on Citrulline Synthesis by Ornithine Transcarbamylase in Human Enterocytes

Chronic Obstructive Pulmonary Disease (COPD) is characterized by chronic systemic hypoxia and low-grade inflammation as well as by an alteration of arginine (ARG) metabolism. As ARG is synthetized from circulating citrulline (CIT), an alteration of CIT homeostasis, particularly its production by ornithine transcarbamylase (OCT) in small intestine could be involved. We hypothesized that hypoxia +/- inflammation, classically associated to COPD, has effects on OCT regulation in enterocytes. This study aims at exploring the effects of hypoxia and inflammation on the production of citrulline by ornithine transcarbamylase (OTC) activity in enterocytes from explant cultures of duodenal tissue.