A multi-isotope approach to studying arginine metabolism in neonatal piglets

摘要

In wk-old piglets, the estimated daily metabolic use of arginine for its various metabolic functions, including protein synthesis, urea cycle function and the synthesis of nitric oxide and creatine is 1.08 g/kg/d, which is higher than the estimated intake of 0.43 g/kg/d from sow's milk (Wu et al, 2000). Endogenous arginine synthesis is then critical for meeting the daily metabolic arginine requirement in piglets. Arginine supplementation improved piglet growth (Kim et al, 2004), providing evidence that the combination of intake from milk and endogenous synthesis is insufficient for optimal piglet performance. Proline has been identified as a major arginine precursor, in vivo (R.O. Ball et al, 2007, unpublished results); however, other precursors may also be important. The objectives of the present research were to determine the effect of arginine intake on arginine synthesis and the rates of conversion among proline, ornithine, citrulline and arginine.