[Protection of interleukin-1 receptor antagonist on epileptiform discharges induced by magnesium-free treatment in developing rat cortical neurons].

OBJECTIVE: To study the protection of IL-1ra in cultured developing neuron injury following Mg(2+)-free-induced epileptiform discharges. METHODS: Rat embryo cortical neurons cultured for 6 d and 17 d were directly exposed to Mg(2+)-free media, or pretreated with IL-1 receptor antagonist or NMDA receptor antagonists before being exposed to Mg(2+)-free media, and then returned to regular media.MTT assay was used to study mitochondrial function injury, laser-scanning confocal microscope to measure [Ca(2+)]i, and real-time RT-PCR to detect gene mRNA expression. RESULTS: (1) MTT conversion rates were higher in neurons pre and co treated with 10 mg/L IL-1ra than those of neurons with only Mg(2+)-free treatment in neurons cultured for 17 d, but not in neurons cultured for 6 d.(2) [Ca(2+)]i was lower in neurons pre and co-treated with 10 mg/L IL-1ra than those of neurons with only Mg(2+)-free treatment, either in neurons cultured for 6 d or in neurons cultured for 17 d, and the effects of IL-1ra on [Ca(2+)]i change were different between neurons cultured for 6 d and neurons cultured for 17 d.(3) Pre and co-treated with 10 mg/L IL-1ra NR1 mRNA expression increase induced by Mg(2+)-free treatment was decreased, either in neurons cultured for 6 d or neurons cultured for 17 d, and this effect showed no difference between neurons cultured for 6 d and 17 d; Pre and co-treated with 10 mg/L IL-1ra NR2A mRNA expression increase induced by Mg(2+)-free treatment in neurons cultured for 17 d was decreased, and NR2A mRNA expression showed no difference between IL-1ra group and age-matched control group, but have no effect on neurons cultured for 6 d; Pre and co-treated with 10 mg/L IL-1ra have NR2B mRNA expression increase induced by Mg(2+)-free treatment was not affected, either in neurons cultured for 6 d or neurons cultured for 17 d. CONCLUSION: Neuroprotection of IL-1Ra in seizure-induced injury is age-dependent. The mech-anism of the neuroprotection of IL-1Ra includes down-regulation of [Ca(2+)]i and others.