甘麦大枣汤对慢性应激抑郁大鼠HPA轴及海马显微结构的影响

目的 研究甘麦大枣汤对慢性应激抑郁模型大鼠HPA轴及海马显微结构的影响,探讨其可能的抗抑郁机制.方法 将SD大鼠随机分为6组:空白组、模型组、氟西汀组(5.4 mg/kg)、甘麦大枣汤高、中、低剂量组(3.84、1.92、0.96 g/kg),采用慢性不可预见性温和应激建立抑郁模型,于造模同时给药,连续21 d.采用糖水消耗实验和旷场测试检测大鼠的抑郁样行为,ELISA法检测大鼠血浆促肾上腺皮质激素释放激素(CRH)、促肾上腺皮质激素(ACTH)、皮质酮(CORT)的变化,HE染色观察大鼠海马CA1区、CA3区及齿状回(DG)区的病理结构变化.结果 与空白组比较,抑郁模型组大鼠蔗糖偏食度及自主活动次数显著下降(P<0.01),血浆CRH、ACTH、CORT含量显著上升(P<0.01),海马CA1区、CA3区以及DG区神经元均萎缩、缺失,损伤明显;与模型组比较,甘麦大枣汤高剂量组大鼠蔗糖偏食度及活动次数均显著提高(P<0.01),血浆ACTH、CORT含量下降(P<0.05),同时海马各区神经元损伤情况得到缓解.结论 甘麦大枣汤能显著改善模型大鼠的抑郁样行为,其作用可能与调节HPA轴高亢,保护海马的损伤有关.

Effects of Ganmai Dazao Decoction on the HPA axis and Microstructure of Hippocampal in Chronic Stress Depression Model Rats

Objective To study the effects of Ganmai Dazao decoction on the HPA axis and hippocampus microstructure in depressive rats induced by chronic stress, and to explore the possible mechanism of its antidepressive role. Methods SD rats were randomly divided into six groups: control group, model group, fluoxetine group (5.4 mg/kg), high, medium and low dose of Ganmai Dazao Tang group (3.84, 1.92, 0.96 g/kg). The model of depression was established by chronic unpre-dictable mild stress, administered simultaneously in modeling, which was administrated with medicines for 21 d. The depression-like behavior in rats was detected by sucrose consumption test and open-field test. The contents of corti-cotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) in plasma were detected by ELISA. HE staining was to disclose pathological changes of hippocampal CA1 structure, CA3 region and dentate gyrus (DG) in rats. Results Compared with control group, sucrose partial eclipse and locomotor activity in rats decreased significantly in model group (P<0.01), and CRH, ACTH, CORT content in plasma had a significant increase (P<0.01), neurons in hippocampal CA1, CA3 and DG region were atrophic or lost, the damage was obvious. Compared with model group, the partial eclipse of su-crose and locomotor activity in high dose of Ganmai Dazao decoction were significantly improved (P<0.01), and the content of plasma ACTH and CORT decreased (P<0.05). Meanwhile, the hippocampal neuronal injury in model group had been alleviated. Conclusion Ganmai Dazao decoction could obviously improve depressive behavior in depressive rats, which might be associated with the regulation of hyperactivity in HPA axis, and reduction of hippocampal damage.