L-GLUTAMINE SUPPLEMENTATION OF A HIGH-FAT DIET REDUCES BODY-WEIGHT AND ATTENUATES HYPERGLYCEMIA AND HYPERINSULINEMIA IN C57BL 6J MICE/

C57BL/6J (B/6J) mice are genetically predisposed to become overweight and develop hyperglycemia if raised on a high fat diet. The purpose of the present study was to explore the effect of dietary supplementatio n of L-glutamine (Gln), an inhibitor of fatty acid oxidation, on the d evelopment of hyperglycemia and excessive weight gain. Groups of 10 ag e- and weight-matched male B/6J mice were raised on one of four diets: 1) a low fat, low sucrose (LL), studied separately, 2) a high fat, Lo w sucrose (HL) diet alone, 3) high fat, low sucrose supplemented with L-glutamine (HL + Gln) and 4) high fat, low sucrose supplemented with L-alanine (HL + Ala). Energy intake, body weight, plasma glucose and i nsulin concentrations were monitored over time. We found no difference in energy intake per unit body weight between any groups after the fi rst 2 wk of feeding. However, the mean + SEM for body weight (27.1 +/- 0.6 g) of the LL group measured at 16 wk was lower (P < 0.05) than th at of the HL group at 37.9 +/- 1.9 g. Also, after 5.5 mo, the mean +/- SEM for plasma glucose and insulin concentrations in the LL group of mice were 6.9 +/- 0.4 mmol/l and 146 +/- 30 pmol/l, which were lower ( P ( 0.05) than those in the HL group at 10.1 +/- 0.9 mmol/l and 438 +/ - 84 pmol/l, respectively. Although both amino acids caused a 10% redu ction (P < 0.05) in body weight compared with HL feeding at wk 16, onl y Gln supplementation resulted in persistent reductions in both plasma glucose and insulin concentrations over 5.5 mo. in another experiment , when Gln was added to the high fat (HL) diet of heavy hyperglycemic animals for 2 mo, body weight gain, hyperglycemia and hyperinsulinemia were attenuated. In conclusion, supplementing glutamine to a high fat diet reduces body weight and attenuated hyperglycemia and hyperinsuli nemia in B/6J mice.