Skip to main content
ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #342734
Title: The intestinal-renal axis for arginine synthesis is present and functional in the neonatal pig

Author
item MARINI, JUAN - Children'S Nutrition Research Center (CNRC)
item AGARWAL, UMANG - Children'S Nutrition Research Center (CNRC)
item ROBINSON, JASON - Children'S Nutrition Research Center (CNRC)
item YUAN, YANG - Children'S Nutrition Research Center (CNRC)
item DIDELIJA, INKA - Children'S Nutrition Research Center (CNRC)
item STOLL, BARBARA - Children'S Nutrition Research Center (CNRC)
item Burrin, Douglas - Doug

Submitted to: American Journal of Physiology - Endocrinology and Metabolism
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2017
Publication Date: 6/13/2017
Citation: Marini, J.C., Agarwal, U., Robinson, J.L., Yuan, Y., Didelija, I.C., Stoll, B., Burrin, D.G. 2017. The intestinal-renal axis for arginine synthesis is present and functional in the neonatal pig. American Journal of Physiology - Endocrinology and Metabolism. doi:10.1152/ajpendo.00055.2017.

Interpretive Summary: The collaboration of two organs (gut and kidney) are required for the synthesis of the amino acid, arginine, in the adult. Because during the neonatal period all the enzymes needed for the synthesis of arginine are present in the gut, it is believed that the "intestinal-renal" axis for arginine synthesis is not present at this early age. In this research we show in neonatal pigs that they do not differ from older animals and that the intestinal-renal axis for arginine synthesis is present and functional. This knowledge may be helpful in the development of supplemental strategies to maintain arginine synthesis when gut metabolism is compromised.

Technical Abstract: The intestinal-renal axis for endogenous arginine synthesis is an interorgan process in which citrulline produced in the small intestine is utilized by the kidney for arginine synthesis. The function of this axis in neonates has been questioned because during this period the enzymes needed for arginine synthesis argininosuccinate synthase and lyase (ASS1 and ASL) are present in the gut. However, evidence of high plasma citrulline concentrations in neonates suggests otherwise. We quantified in vivo citrulline production in premature (10 d preterm), neonatal (7 d old) and young pigs (35 d old) using citrulline tracers. Neonatal pigs had higher fluxes (69 umol / (kg/h); P <0.001) than premature and young pigs (43 and 45 umol / (kg/h), respectively). Plasma citrulline concentration was also greater in neonatal pigs than in the other age groups. We also determined the site of synthesis and utilization of citrulline in neonatal and young pigs by measuring organ balances across the gut and the kidney. Citrulline was released from the gut and utilized by the kidney in both neonatal and young pigs. The abundance and localization of the enzymes involved in the synthesis and utilization were determined in intestinal and kidney tissue. Despite the presence of ASS1 and ASL in the neonatal small intestine, the lack of co-localization with the enzymes that produce citrulline results in the release of citrulline by the PDV and its utilization by the kidney to produce arginine. In conclusion, the intestinal-renal axis for arginine synthesis is present in the neonatal pig.