线粒体膜电位与皮质酮对原代培养海马细胞的毒性作用

采用MTT法和激光共聚焦显微术观察皮质酮对原代培养海马神经细胞的存活率及其线粒体膜电位的影响。结果表明,在低糖、无血清培养条件下,皮质酮可剂量依赖地降低海马神经元及神经胶质细胞的存活率,在同等剂量下以神经元损伤更为显著。给予高浓度葡萄糖（25mmol/L）可明显拮抗皮质酮对海马神经元的毒性作用。进一步研究表明,皮质酮（10^-6-10^-5mol/L）可引起海马神经元线粒体膜电位明显下降,此作用亦可被高浓度葡萄糖所对抗。结果提示,在相同处理因素条件下,皮质酮以损伤神经元为主。皮质酮可降低海马神经元的存活率及线粒体膜电位,给予高浓度葡萄糖具有明显的改善作用。线粒体膜电位的下降可能是皮质酮引起神经元损伤的机制之一。

Correlation between mitochondrial membrane potential and neurotoxic effect of corticosterone on primary cultured hippocampal cells

Experiments were carried out to study the toxic effect of corticosterone (CORT) on primary cultured hippocampal cells and its relationship with mitochondrial membrane potential (MMP). Hippocampal cell survival and MMP were assessed by MTT and laser scanning confocal microscopy respectively. The results indicated that the survival rate of hippocampal neurons and astrocytes was dose dependently reduced in the hypoglycemic (3 5 mmol/L) and serum free medium for 24 h. With the same concentration of CORT, the toxic effect of CORT on hippocampal neurons was more serious than that on astrocytes. A supplement of high concentration of glucose (25 mmol/L) greatly improved the survival rate of hippocampal neurons cultured in the hypoglycemic and serum free medium. The disruption of MMP was induced by CORT (10( 6) mol/L) in hippocampal neurons cultured in hypoglycemic and serum free medium and antagonized by high concentration of glucose. It is therefore suggested that hippocampal neurons are more sensitive to the toxic effect of CORT in comparison with astrocytes. Neurotoxic effect of CORT can be reduced by high concentration of glucose. CORT-induced reduction of MMP may be one of the mechanisms for its neurotoxicity.