Mitochondrial damage and expressions of Fas and Bax in the hippocampal neurons after status epilepticus of different latencies in rats
SUN Jian-Ying, CHI Zhao-Fu, WU Wei, LIU Xue-WU, ZHAO Xiu-He. Department of Neurology, Qilu Hospital, Shandong University, Jinan 250012, China
Objective To observe the mitochondrial ultrastructure damage and mRNA expressions of Fas and Bax in the hippocampal neurons after status epilepticus (SE) of different latencies in rats.Methods SE was induced by intraperitoneal injection of 12 mg/kg kanic acid (Group A) or tail vein injection of 10 mg/kg kanic acid (Group B) in rats. The rats were killed 3, 6, 24, 48 and 72 hrs after SE and the hippocampus were taken out. The mitochondrial ultrastructures were observed under an electron microscope. Fas and Bax mRNA were determined by semiquantitative RT-PCR. Ten rats without any treatment were used as the control group.Results The latency was 97±11 min, and the swelling mitochondrion and apoptotic neurons were observed in Group A. The latency was 48±13 min, the mitochondrion were swelling with ruptured membrane, and the neurons were necrotic in Group B. Fas and Bax mRNA began to increase at 6 hrs after SE, reached a peak at 48 hrs and remained higher at 72 hrs in Group A compared with the control group. There were no differences in Fas and Bax expressions between Group B and the control group.Conclusions SE of different latencices resulted in different degrees of mitochondrial damages, which determined the molecular mechanisms of neuronal death.