Neuroprotective effects of leptin following kainic acid-induced status epilepticus.
Scorpion venom is a traditional antiepileptic medicine in Asia. We examined the effects of scorpion venom heat-resistant protein (SVHRP) on seizure behavior of rats with kainate-induced epilepsy and expression of proenkephalin (pENK) in their hippocampus. Subcutaneous injections of convulsive doses of kainic acid (KA, 10 mg/kg) evoked acute epileptic seizures; the intensity of such seizures was measured after subsequent injections of lower (subthreshold in the norm) doses of KA (5 mg/kg). Scorpion venom heat-resistant protein in a dose of 125 μg/kg was given in a part of the animals through i.p. injections daily during 10 days; rats of the control groups were injected with normal saline. Behavioral indices were measured, and the hippocampus was taken for pENK mRNA estimation by RT-PCR analysis. The mean behavioral score of seizure sensitivity in the SVHRP-treated group was smaller significantly (P < 0.05) compared to that in the control group (1.19 vs 2.93). The pENK mRNA level was dramatically greater in hippocampal neurons of KA-treated rats with a high seizure sensitivity, while in the SVHRP-treated group the respective index was significantly lower. Thus, SVHRP inhibits behavioral seizures in epilepsy and reverses the abnormally increased pENK mRNA in hippocampal neurons of such animals.