Leptin promotes the neurorehabilitation of seizure-induced brain damage / 中华物理医学与康复杂志

ABSTRACT

Objective To explore the effect of leptin on neurorehabilitation and on the expression of dopamine receptor D2 (Drd2) and cytosolic phospholipase A2 (cPLA2) in the cerebral cortex after convulsive brain injury.Methods Five-day-old Sprague-Dawley rats were randomly assigned to a control group (CONT),a leptin injection control group (Leptin),a seizure group (RS),or a seizure with leptin injection group (RS+Leptin).The rats in the RS group and the RS+Leptin group were injected intraperitoneally with lithium chloride (5 mEq/kg) and pilocarpine (320 mg/kg) on day 6,and then scopolamine methyl chloride (1 mg/kg) 30 minutes later to block the peripheral effect of pilocarpine.The animals in the Leptin and RS+Leptin groups were then given leptin (4 mg/kg,i.p.) injections daily from days 8 to 14.The animals' plane righting reflex and negative geotaxis reaction reflex were observed on day 23.The open field test was performed on D30.Real-time reverse-transcription polymerase chain reactions (RT-PCRs) were used to detect the expression of Drd2 and cPLA2 mRNA in the rats' cerebral cortexes on day 34.Results There were significant differences in the plane righting times and negative geotaxis reflexes among the four groups,with those in the RS and RS+Leptin groups significantly longer than among the controls.Both reflexes were significantly quicker in the RS + Leptin group than in the RS group.There were also significant differences in the locomotor scores in the open field test among the four groups,with the average scores in the RS and RS+Leptin groups significantly higher than in the other two groups.The RS+Leptin group's average was significantly higher than that of the RS group.The expression of Drd2 was significantly higher in the leptin,RS and leptin +RS groups than in the control group,and that of the RS and leptin+RS groups was significantly higher than that of the Leptin control group.The expression of cPLA2 in the Leptin and RS groups was significantly higher than in the CONT group,while that of the RS + Leptin group was significantly lower than in the Leptin and RS groups.Conclusions Leptin has a neurorehabilitation effect on the behavioral impairment caused by seizures,at least in neonatal rats.Its neuroprotective mechanism may be related to the regulation of Drd2-mediated cPLA2 expression in the cerebral cortex.