Infusion of glucagon-like peptide 2 with an arginine deficient diet increases endogenous arginine synthesis from proline in parenterally-fed neonatal piglets

Parenteral feeding can be used to induce intestinal atrophy in piglets, and this atrophy is believed to be associated with the inability of parenterally-fed piglets to maintain arginine status via synthesis. Glucagon-like peptide 2 (GLP-2) has been shown to maintain intestinal structure and blood flow during intravenous feeding. GLP-2 infusion was hypothesized to increase the rate of endogenous arginine synthesis from proline in parenterally-fed piglets receiving an arginine deficient diet. Male piglets (n = 10, 1.5–2.0 kg), fitted with jugular vein catheters for diet and isotope infusion, and femoral vein catheters for blood sampling (d 0), were allocated to a continuous infusion of either GLP-2 (10 nmol/kg/d) or saline into the jugular vein. Piglets received 2 d of a complete diet, followed by 5 d of an arginine deficient (0.60 g/kg/d) diet. A primed, constant infusion of [guanido-¹⁴C]arginine measured arginine flux (d 6), and of [U-¹⁴C]proline (d 7) measured proline conversion to arginine. There were no differences between groups in plasma ammonia, urea and arginine concentrations and arginine flux. Piglets receiving GLP-2 had a greater jejunal mucosal mass (P = 0.003) and a two-fold greater rate of arginine synthesis from proline (P = 0.03). This study indicates that the intestinal metabolism of circulating precursors may be important for arginine synthesis in parenterally-fed neonates.