电针对慢性疼痛抑郁共病大鼠海马组织Cyt-C、Caspase-9表达的影响

Effects of Electroacupuncture on Cyt-C and Caspase-9 Expression in Hippocampal Tissue of Rats with Chronic Pain and Depression Comorbidity

目的 观察电针“合谷”“太冲”对慢性疼痛抑郁共病(CPDC)大鼠海马组织细胞色素C(Cyt-C)、胱天蛋白酶-9(Caspase-9)表达的影响,探讨电针治疗CPDC的可能机制。方法 60只SD大鼠随机分为假手术组、模型组、药物组和电针组,每组15只。采用左后足足底2次注射完全弗氏佐剂复制CPDC模型。电针组于双侧“合谷”“太冲”行电针干预,20 min/次,药物组予10 mg/kg度洛西汀混悬液灌胃,连续14 d。分别于首次注射后7、14、21、28 d检测机械缩足阈值及热缩足潜伏期,14、28 d检测悬尾不动时间和糖水偏好率,尼氏染色观察海马神经元形态及尼氏体数量,Western blot、免疫组化检测海马组织Cyt-C、Caspase-9蛋白表达。结果 与假手术组比较,模型组大鼠机械缩足阈值、热缩足潜伏期减少(P<0.01),悬尾不动时间增加(P<0.01),糖水偏好率下降(P<0.01),海马神经元排列稀松,神经元受损、丢失,尼氏体数量减少(P<0.01),海马神经元细胞凋亡率升高(P<0.01),海马组织Cyt-C、Caspase-9表达及cleaved-Caspase-9/Caspase-9比值升高(P<0.01);与模型组比较,药物组和电针组大鼠机械缩足阈值、热缩足潜伏期增加(P<0.01),悬尾不动时间减少(P<0.01),糖水偏好率升高(P<0.01),海马神经元丢失减少,细胞排列较整齐,核仁清晰,尼氏体数量增加(P<0.01),海马神经元细胞凋亡率降低(P<0.01),海马组织Cyt-C、Caspase-9表达及cleaved-Caspase-9/Caspase-9比值降低(P<0.01)。结论 电针“合谷”“太冲”可减轻CPDC模型大鼠疼痛及抑郁行为,发挥神经保护作用,其机制可能与抑制海马组织Cyt-C、Caspase-9蛋白表达,抑制海马神经元凋亡有关。

Objective To observe the effects of electroacupuncture(EA)at“Hegu”and“Taichong”on the expressions of cytochrome C(Cyt-C)and Caspase-9 in the hippocampus of rats with chronic pain and depression comorbidity(CPDC);To explore its potential mechanism for the treatment of CPDC.Methods A total of 60 SD rats were randomly divided into sham-operation group,model group,medication group and EA group,with 15 rats in each group.The CPDC model was induced by twice injection of complete Freund’s adjuvant into the plantar of the left hind paw. EA group was applied to bilateral “Hegu” and “Taichong” for 20 min, the medication group weretreated with duloxetine suspension 10 mg/kg by gavage for 14 days. The mechanical paw withdrawal threshold andthermal withdrawal latency were measured on day 7, 14, 21 and 28 after the first injection, tail suspension test andsucrose preference test were performed on day 14 and 28, Nissl staining was used to observe hippocampal neuronsand the number of Nissl body, the protein expressions of Cyt-C and Caspase-9 in hippocampal tissue were detectedby Western blot and immunohistochemistry. Results Compared with the sham-operation group, the mechanical pawwithdrawal threshold and thermal withdrawal latency of the model group significantly decreased (P<0.01), the tailsuspension immobility time increased (P<0.01), the percentage of sucrose preference decreased (P<0.01), theneurons were thinly arranged, the neurons were damaged and lost, and the number of Nissl body were less (P<0.01), the apoptotic rate of hippocampal neurons increased (P<0.01), the expression of Cyt-C, Caspase-9 andcleaved-Caspase-9/Caspase-9 ratio in hippocampal tissue increased (P<0.01). Compared with the model group, themechanical paw withdrawal threshold and thermal withdrawal latency of the EA group and medication groupsignificantly increased (P<0.01), the tail suspension immobility time decreased (P<0.01), the percentage of sucrosepreference increased (P<0.01), the loss of neurons in hippocampus was reduced, the cells were arranged neatly, andthe nucleoli were clear, the number of Nissl body increased (P<0.01), the apoptotic rate of hippocampal neuronsdecreased (P<0.01), and the expression of Cyt-C, Caspase-9 and cleaved-Caspase-9/Caspase-9 ratio in hippocampaltissue decreased (P<0.01). Conclusion EA at “Hegu” and “Taichong” can alleviate pain and depression in CPDCrats, which may be related to inhibiting the expressions of Cyt-C and Caspase-9 in hippocampal tissue and inhibitingthe apoptosis of hippocampal neurons, thus playing a neuroprotective effect.