Abstract:

Objective   To investigate the alteration of mitochondrial fission and fusion in hippocampus of rats with status epilepticus (SE). Methods   Male Wistar rats were randomly divided into five groups：normal control group and epileptic group (4, 8, 24 and 72 h after SE). The alteration of mitochondrial fission and fusion in hippocampus of rats were evaluated at different time points after SE. Western blotting and PCR were used to estimate the expression of dynamin related protein1 (Drp1), human mitochondrial fission protein1 (hFis1), mitofusin1 (Mfn1) and optic atrophy1 gene protein1 (Opa1). Immunohistochemistry was used to estimate the expressions of Drp1 and Opa1 in neurons of hippocampal CA3 region 24 h after SE. Results   Mitochondrial fission proteins Drp1and hFis1 began to increase 4 h after SE, with a peak at 24 h and still elevated 72 h after SE. Whereas mitochondrial fusion proteins Mfn1and Opa1 increased transiently at 4 h after SE and decreased sharply thereafter, falling into the bottom at 24 h. The number of neurons expressed Drp1 at 24 h after SE was significantly higher than that in normal control group (P＜0.05), while the number of neurons expressed Opa1 was significantly lower than that in normal control group(P＜0.05). Conclusion   SE leads to imbalanced mitochondrial fission and fusion, shown by the enhanced mitochondrial fission and the declined mitochondrial fusion.

Key words: Status epilepticus; Hippocampus; Mitochondria; Fission; Fusion