Aspartate-induced neuronal necrosis in infant mice: protective effect of carbohydrate and insulin.

Infant mice given large doses of glutamate or aspartate develop hypothalamic neuronal necrosis. Studies by others demonstrated that simultaneous administration of carbohydrate or prior injection with insulin markedly decreased glutamate-induced neuronal damage. We investigated whether carbohydrate and insulin exert a similar protective effect against aspartate-induced neuronal necrosis. Eight-day-old mice administered aspartate at 750 and 1000 mg/kg body weight developed neuronal necrosis (45.9 +/- 7.2 and 80.8 +/- 17.3 necrotic neurons/section, respectively). When carbohydrate (1 g/kg body weight) was administered simultaneously no lesions were detected in mice administered 750 mg/kg body weight aspartate, while 30.1 +/- 14.2 necrotic neurons/section were noted at 1000 mg aspartate/kg body weight. Mice administered 1000 mg/kg body weight aspartate with prior injection of insulin had 28.4 +/- 12.6 necrotic neurons/section, while 4.2 +/- 1.4 necrotic neurons/section were noted in insulin treated mice given 750 mg aspartate/kg body weight. Carbohydrate and insulin treatments has only minimal effects on plasma aspartate concentrations.