Effect of carbohydrate ingestion on plasma aspartate concentrations in infant mice administered sodium L-aspartate

Previous studies of infant pigs have demonstrated that simultaneous ingestion of carbohydrate (1 g/kg body weight) and glutamate (300 mg/kg body weight) resulted in markedly lower mean peak plasma glutamate concentration and a smaller area under the plasma glutamate concentration-time curve (AUC) than ingestion of the equivalent amount of glutamate alone. This study was carried out to investigate whether a similar carbohydrate-induced effect occurred with the other dicarboxylic amino acid, aspartate. Eight-day-old mice were administered sodium L-aspartate at 250, 500 and 1000 mg/kg body weight with and without 1.0 g/kg body weight of partially hydrolyzed cornstarch. Mean peak plasma aspartate concentration and plasma aspartate AUC values increased in proportion to the aspartate dose. The addition of carbohydrate to the aspartate solution had no significant effect on either mean peak plasma aspartate concentrations or AUC values at aspartate doses of 250 and 500 mg/kg body weight. A modest, but significant effect of carbohydrate was noted on the mean peak plasma aspartate levels in animals administered 1000 mg/kg body weight aspartate (P less than 0.05, Student's t-test). However, analysis of variance showed no significant carbohydrate effect and plasma AUC values were not significantly affected. These data indicate that carbohydrate affects the metabolism of aspartate and glutamate differently.