改善氧化应激平衡和逆转NET及5-HTT表达异常涉及文拉法辛的抗抑郁作用

Improving oxidative stress response and reversing abnormal expression of hippocampus NET and 5-HTT involved in anti-depressive effect of venlafaxine

目的探讨文拉法辛抗慢性不可预见刺激所致大鼠抑郁症作用与氧化应激和海马去甲肾上腺素转运体(norepinephrine transporter,NET)、5羟色胺转运体(serotonin transporter,5-HTT)表达的关系。方法♂SD大鼠80只,根据开场实验得分分为4组,即正常对照组(NG)、模型组(MG)、文拉法辛处理的正常对照组(VNG)和文拉法辛处理的模型组(VMG)。采用孤养结合慢性不可预见刺激(chronic unpredictable stress,CUS)方法建立大鼠抑郁模型;给药组每天给予文拉法辛(23.4 mg·kg-1·d-1),NG和MG组每天给予同体积溶剂。采用强迫游泳(force swimming)实验评价大鼠的抑郁行为,生物化学方法检测大鼠血清的超氧化物岐化酶(superoxide dismutase,SOD)活性与丙二醛(malondialdehyde,MDA)含量,实时定量RT-PCR分析海马5-HTT、NET的mRNA表达,Western blot测定海马5-HTT、NET的蛋白表达。结果相对于NG组,MG组大鼠在强迫游泳实验中的不动时间明显增加,SOD活性降低,血清MDA含量升高,海马5-HTT表达明显下降,而NET的表达明显升高。文拉法辛干预能阻遏CUMS诱导的上述变化;文拉法辛处理对正常对照大鼠的行为、SOD、MDA和5-HTT及NET表达无明显影响。结论文拉法辛抑制CUS诱导大鼠出现焦虑抑郁样行为的机制至少部分与其改善脑内氧化应激平衡,逆转5-HTT和NET异常表达有关。

Aim To investigate if anti-depressive effect of venlafaxine was associated with improving oxi-dative stress and expression of hippocampus NET and 5-HTT in rat model induced by CUS. MethodsEighty SD male rats were randomly divided into four groups：model group（MG）,normal group（NG）, ven-lafaxine-treated normal group （ VNG ） , and venlafax-ine-treated model group （ VMG） . VNG and VMG were given venlafaxine （23. 4 mg·kg-1 ·d-1 ） once daily;NG and MG were given the same volume solvent. Soli-tary condition with chronic unpredicted stress （ CUS ） was taken to establish rat depression model. The force swimming test was used to evaluate the behavior chan-ges of experimental rats. The malondialdehyde （ MDA） level and activity of superoxide dismutase （ SOD ） in serum were determined by biochemical methods. The mRNA and protein expressions of NET and 5-HTT in hippocampus were determined by Real-Time Reverse transcription polymerase chain reaction （ real-time RT-PCR） and Western blot （ WB） , respectively. Results Compared with NG rats, obviously increasing immo-bile time of rats in force swimming test and serum MDA level, as well as significantly decreasing SOD activity in serum was observed with clearly decreasing 5-HTT expression and elevating NET expression in hippocam-pus of MG rats. The treatment of venlafaxine distinctly suppressed changes above from CUS-induced rats. However, significant changes failed to be found in VNG rats. Conclusion The anti-depressive effect of venlafaxine may at least partly involve in improving ox-idative stress/anti-oxidative stress balance and revers-ing abnormal expression of NET and 5-HTT.