Mitochondrial damage and expressions of Fas, Bax and Caspase-3 in hippocampal neurons of rats induced by different ways of administration
- VernacularTitle:两种不同给药途径诱发大鼠海马神经元线粒体损伤及Fas、Bax、Caspase-3表达
- Author:
Jianying SUN
;
Shuhai TANG
;
Zhaofu CHI
;
Wei WU
;
Xuewu LIU
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2006;10(38):181-183
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Status epilepticus can result in neuronal injury.OBJECTIVE: To observe the mitochondrial ultrastructural damage and the changes of Fas, Bax and Caspase-3 expressions in hippocampal CA3 neurons of rats of different kindling, so as to provide theoretical evidence for the neuronal injury after epilepsy.DESIGN: A randomized c ntrol animal experiment.SETTINGS: Department of Neurology and Department of Anesthesiology,Qilu Hospital of Shandong University.MATERIALS: The experiments were carried out in the pathological laboratory of Shandong Academy of Medical Sciences between March and July2005. Totally 150 adult male SD rats of 260-300 g were provided by the experimental animal center of Shandong University (SCXK20030004), they were raised at room temperature and were free to the access of food and water.METHODS: The adult male Sprague Dawley (SD) rats were divided into intraperitoneal injection of kainic acid group and caudal venous injection of kainic acid group respectively ac cording to the method of random number table, and the rats were administrated by kainic acid injected intraperitoneally (12 mg/kg) and via caudal vein (10 mg/kg) respectively. Each group was divided into 5 subgroups, which were 3, 6, 24, 48 and 72 hours after status epilepticus groups respectively. Twelve successfully induced rats were selected from each subgroup, hippocampi were removed at different time points after the termination of status epilepticus, 2 were used for examination under electron microscope, 5 for the reverse transcription-polymerase chain reaction (RT-PCR) detection of Fas and Bax, and 5 for the immunohistochemical assay of Caspase-3. Another 12 rats were used as normal controls without any treatment. The materials were taken at24 hours after corresponding status epilepticus in the control group, and the specific distributions were the same as those in the subgroups. The mitochondrial structure was observed under electron microscope, the levels of Fas and Bax mRNA were detected with semi-quantitative RT-PCR, and the expression of Caspase-3 protein was determined with the immunohistochemical assay.MAIN OUTCOME MEASURES: ① Results of ultrathin section under transmission electron mcroscope; ② RT-PCR results; ③ Immunohistochemical results.RESULTS: Totally 132 rats were involved in the analysis of results. ①Mitochondrial structure under electron microscope: In the intraperitoneal injection group, the mitochondria swelled, and the neurons showed characters of apoptosis. In the caudal venous injection group, the mitochondria swelled, and accompanied by the membranous collapse, and the neurons manifested the necrosis. ② No expression of Fas and Bax was detected in the control group and caudal venous injection. In the intraperitoneal injection group, Fas expression appeared at 6 hours after status epilepticus, increased at 24 hours, reached the peak value at 48 hours, and lasted till 72 hours. ③ The Caspase-3 expressions began to increase 6 hours after status epilepticus in both the intraperitoneal injection group and caudal venous injection group(10.27±0.34, 15.21±0.34; P ＜ 0.001), and reached the peak values at 24 hours (25.36±0.47, 28.23±0.47; P ＜ 0.001); The higher expression of Caspase-3 lasted till 72 hours in the intraperitoneal injection group, but sharply decreased in the caudal venous injection group.CONCLUSION: Two different methods of administration result in different severity of mitochondrial damage and different expressions of Fas, Bax and Caspase-3, which further determines the molecular mechanisms of neuronal death.
