Protective effect of carnosine on febrile seizures in immature mice.

Febrile seizures (FSs) are the most common type of convulsions in childhood and complex FSs represent an increased risk for development of temporal lobe epilepsy. The aim of this study was to analyze the anticonvulsant effects of carnosine, an endogenous dipeptide composed of alanine and histidine, on hyperthermia induced seizure in immature mice. Injection of carnosine significantly increased the latency and decreased the duration of FSs in a dose-dependent manner. In addition, histidine had similar effects on FSs as carnosine. The protective effect of carnosine or histidine was completely abolished by α-fluoromethylhistidine (α-FMH), a selective and irreversible histidine decarboxylase inhibitor, or in histidine decarboxylase deficient (HDC-KO) mice. Peripheral carnosine administration increased the level of carnosine, histidine and histamine in the cortex and hippocampus of mice pups, but decreased glutamate contents in the cortex and hippocampus. These results indicate that carnosine can protect against FSs in mice pups through its conversion to histamine, suggesting that it may serve as an efficient anti-FSs drug in the future.