The effect of glutamine and dihydroxyacetone supplementation on food intake, weight gain, and postprandial glycogen synthesis in female Zucker rats.
OBJECTIVE
We sought to test the hypothesis that increasing postprandial hepatic glycogen synthesis rate would decrease food intake and growth rate in obese Zucker rats.


METHODS
Supplements of glutamine, with and without dihydroxyacetone (DHA), which have previously been shown to stimulate hepatic glycogen synthesis, were administered in the diet of obese Zucker rats for periods of 1 and 3 wk.


METHODS
Food intake and body weight were monitored throughout the experiments. At the end of the feeding period the rats were fed a test meal and injected with (3)H(2)O to measure in vivo rates of glycogen and lipid synthesis. Final plasma glucose and triacylglycerol and hepatic glycogen content were also determined. Carcass fat and water contents were also measured in the 3-wk study.


RESULTS
Dietary glutamine had no effect on food intake, weight gain, or body composition. Addition of DHA caused a reduction in food intake and weight gain and a stimulation of in vivo hepatic glycogen synthesis after 1 wk, but these changes were abolished by the end of 3 wk. Hepatic lipogenesis in vivo was increased by DHA treatment for 1 and 3 wk.


CONCLUSIONS
Stimulation of hepatic glycogen synthesis by DHA treatment was associated with a reduction in food intake. However, the effect of DHA on glycogen synthesis and food intake disappeared after 3 wk of supplementation.
Obeid
Omar A
OA
Department of Food Technology and Nutrition, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon.
Jamal
Zeina M
ZM
Hwalla
Nahla
N
Emery
Peter W
PW
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D004032:Diet; D019587:Dietary Supplements; D004098:Dihydroxyacetone / Q000008:administration & dosage*; D004435:Eating / Q000187:drug effects*; D005260:Female; D005502:Food; D005973:Glutamine / Q000008:administration & dosage*; D006003:Glycogen / Q000032:analysis / Q000096:biosynthesis*; D008055:Lipids / Q000096:biosynthesis; D008099:Liver / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D009765:Obesity / Q000378:metabolism / Q000628:therapy*; D051381:Rats; D011924:Rats, Zucker; D013997:Time Factors; D014280:Triglycerides / Q000097:blood; D014316:Tritium; D015430:Weight Gain / Q000187:drug effects*
D001786:Blood Glucose; D008055:Lipids; D014280:Triglycerides; D005973:Glutamine; D014316:Tritium; D006003:Glycogen; D004098:Dihydroxyacetone