The plasma fluxes of ornithine (Orn), arginine (Arg), and citrulline (Cit) and rate of conversion of labeled ornithine- to-citrulline (Q(Orn → Cit)) were estimated in six healthy adult men receiving an arginine-rich or arginine-free L-amino acid- based diet, each for 6 days. On day 7 an 8-h (3- h fast, 5-h fed) primed continuous intravenous infusion of L-[guanido- 15N,15N] arginine, L-[ureido-13C]citrulline, L-[5,5,2H2]ornithine, and L-[5,5,5-2H2]leucine was conducted. Mean citrulline fluxes (μmol · kg-1 · h-1) were 10.4-13.6 for the various conditions and/or diets and remained unchanged (P > 0.05). Arginine flux was lowered (P < 0.01) by 38% for fed state during arginine-free period. Ornithine fluxes for arginine- rich were (P < 0.01) reduced with the arginine-free diet. Rates of Q(Orn → Cit) declined by 30% (P < .05) during the fed arginine-free period. Short- term restriction in the dietary supply of arginine did not alter the rate of whole body nitric oxide synthesis. One subject showed a very high output of nitrate on arginine-free diet (6 times average for remaining subjects).
|Original language||English (US)|
|Journal||American Journal of Physiology - Endocrinology and Metabolism|
|Issue number||2 31-2|
|State||Published - Jan 1 1995|
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Physiology (medical)