Dietary arginine, insulin secretion, glucose tolerance and liver lipids during repletion of protein-depleted rats.
Male Sprague-Dawley rats (approximately 500 g) were fed a very low protein diet (0.5% lactalbumin) for 14 weeks. The average weight loss was 195 g. Following protein depletion the rats were randomly assigned to 5 groups and repleted for 15 days with a purified diet containing 20% protein equivalent as L-amino acids with arginine comprising 0, 0.25, 0.5, 0.75 or 1.0% of the total diet. The absence of dietary arginine during repletion significantly reduced weight gain and efficiency of feed utilization with no apparent change in feed intake. Livers of animals fed 0 and 0.25% arginine were slightly heavier and contained a greater concentration of total lipids than livers from other groups. Intravenous glucose tolerance tests performed on the animals fed 0, 0.5 and 1.0% arginine gave k coefficients for glucose disappearance which were significantly greater (P less than .01) for 1.0% arginine (0.12) than for 0.5% arginine (.056) or 0% arginine (.045). Plasma insulin for the 1.0% arginine group peaked at 5 min following glucose injection, and declined steadily to near basal levels at 45 min. Plasma insulin for animals repleted with 0 and 0.5% arginine was elevated to a lesser degree than for 1.0% arginine by 5 min but remained above basal levels throughout the experiment and there was a concurrent decrease in the rate of glucose disappearance. The insulinogenic index (formula: see text) was significantly greater (P less than .01) with 1.0% and 0.5% arginine than with 0% arginine. These data suggest that glucose intolerance during arginine deficiency is related to decreased insulin release immediately following glucose administration and possibly a mild insulin resistance.
D000818:Animals; D001120:Arginine / Q000172:deficiency*; D004044:Dietary Proteins / Q000008:administration & dosage*; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D009963:Orotic Acid / Q000378:metabolism; D051381:Rats
D004044:Dietary Proteins; D007328:Insulin; D009963:Orotic Acid; D001120:Arginine; D005947:Glucose