Glutaric acidemia type I (GA-I) is an inherited
metabolic disease characterized by striatal degeneration,
seizures, and accumulation of
glutaric acid (GA). Considering that GA impairs energy metabolism and induces reactive species generation, we investigated whether the acute administration of
creatine, an
amino acid with
antioxidant and ergogenic properties, protects against the
seizures and neurochemical alterations (inhibition of Na(+),K(+)-
ATPase and increased protein carbonylation) induced by the intrastriatal injection of GA (4 micromol/striatum). We also investigated whether
creatine protected against the GA-induced inhibition of
glutamate uptake in vitro.
Creatine administration (300 mg/kg, p.o.) decreased
seizures (evidenced by electrographic changes), protein carbonylation and Na(+),K(+)-
ATPase inhibition induced by GA. However,
creatine, at a dose capable of fully preventing GA-induced protein carbonylation (50 and 150 mg/kg, p.o.), did not prevent convulsions and Na(+),K(+)-
ATPase inhibition, suggesting that the
anticonvulsant activity of
creatine in this experimental model is not related to its
antioxidant action.
Creatine also protected against the GA-induced inhibition of l-[(3)H]
glutamate uptake in synaptosomes, suggesting that
creatine may reduce the deleterious effects of GA by maintaining
glutamate uptake in the synaptic cleft. Therefore, considering that
creatine significantly attenuates the deleterious effects of GA assessed by behavioral and neurochemical measures, it is plausible to propose the use of this
amino acid as an adjuvant
therapy in the management of glutaric acidemia.