Arginine requirement of mature protein-malnourished rats for maximal rate of repletion.
Male Sprague-Dawley rats (initial weight 400 g) were fed a 0.5% lactalbumin diet containing required amounts of all other known essential nutrients for 14 weeks. The body weights averaged 250 g after depletion when the animals were randomly assigned to four groups of four or five. Rats of one group were killed for baseline analyses on day 0 of repletion. The remaining three groups were repleted for 14 days with a complete L-amino acid diet containing 20% protein equivalent and 0, 0.75 or 1.5% Arg . HCl. Daily feed intakes averaged 11, 15 and 17 g and daily weight gains were 3.3, 7.4 and 8.3 g, respectively. Average values for corresponding groups were: nitrogen balance--116, 187 and 190 mg/day; urinary orotate--4.6, 0.8 and 0.15 mg/day; carcass lipid--27, 37 and 40 g/100 g dry matter. Liver weights per 100 g body weight for 0 arginine exceeded other groups by 40%. There were no differences in creatinine index, nor in plasma concentrations of insulin, glucagon and albumin. The maximal rate of recovery from protein-calorie malnutrition of mature rats required an exogenous source of arginine. Urinary orotic acid excretion provided a reliable measure for determining when arginine needs for maximal rate of repletion were not met.
D000818:Animals; D001120:Arginine / Q000627:therapeutic use*; D001823:Body Composition; D001835:Body Weight; D004044:Dietary Proteins / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D008099:Liver / Q000033:anatomy & histology; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D009929:Organ Size; D009963:Orotic Acid / Q000652:urine; D011488:Protein Deficiency / Q000178:diet therapy*; D051381:Rats
D004044:Dietary Proteins; D009963:Orotic Acid; D001120:Arginine; D009584:Nitrogen