慢性应激对大鼠肾素—血管紧张素系统和血管内皮的影响及电针的干预作用

【作者】 宋洪涛；

【导师】 李志刚；

【作者基本信息】 北京中医药大学 ， 针灸推拿学， 2014， 博士

【摘要】 抑郁症与心血管疾病相互影响已逐渐被科研人员所重视,但相关的病理机制尚未清楚,有研究认为,血管内皮细胞的损害在两者之间相互影响,内皮功能的损伤与心血管疾病关系密切,临床报道抑郁症患者同样存在血管内皮功能障碍,但尚未有相关实验研究报道,抑郁对血管内皮形态和功能的影响将是本实验研究的重点。有资料证明,抑郁症患者同时也存在着血管紧张素Ⅱ(Angiotensin Ⅱ, AngⅡ)水平升高,临床及实验研究均证实,机体在抑郁状态时存在氧化／抗氧化应激系统失衡,研究表明,肾素-血管紧张素系统(Renin-angiotensin system, RAS)的过度激活可以通过诱导机体氧化应激对内皮功能造成伤害,是否在抑郁症患者机体内同样存在着RAS的过度激活,诱导机体氧化／抗氧化应激失衡,导致内皮功能障碍,将是本实验研究的主要问题之一抑郁症的发生多伴随褪黑素(Melatonin, MT)含量的下降,近年来MT在抑郁症的研究中多以其调节睡眠为主要的研究方向,但作为机体内已知的作用最强的自由基清除剂,其具有强大抗氧化的作用在抑郁症研究中尚未有人涉及,MT含量的下降是否会影响抑郁症机体组织的氧化应激／抗氧化应激平衡,以及是否继而造成其他躯体疾病,相关文献尚未见报道,本实验研究中将对抑郁症与MT的关系,以及MT与抑郁状态时机体氧化／抗氧化应激失衡的相关性这几方面进行探讨。针灸对疾病的治疗是多靶点、多角度进行的,针灸对抑郁症的改善作用已经被临床和实验研究证实,针灸在其他疾病中对RAS调节作用和对内皮功能的改善作用均有文献支持,但电针对抑郁症患者RAS和内皮功能的影响尚未见相关报道,本实验将从抗抑郁、抗氧化应激以及非药物三个层次进行研究,采取氟西汀治疗,外源性褪黑素和脉冲电针三种干预措施观察它们对抑郁模型大鼠的RAS、氧化应激和内皮功能的影响进行探讨,分析抑郁与血管内皮损伤的关系。研究方法和结果1.慢性不可预知性温和应激(CUMS)结合孤养的方法复制抑郁模型大鼠,采用敞箱试验、体质量变化和糖水实验三种方法验证抑郁模型大鼠复制成功与否,实验前,各组大鼠在在敞箱实验、体质量变化及糖水消耗量方面均无显著性差异,在21天的刺激后,模型对照组大鼠在敞箱试验中的水平运动次数和垂直运动次数、体质量增加量和糖水摄入量这几方面均低于空白对照组,且有显著性差异(P<0.01),说明复制抑郁模型成功；与模型对照组比较,氟西汀组和脉冲电针组大鼠在以上几方面均明显具有改善作用,有统计学意义(P<0.05),脉冲电针组大鼠在敞箱试验中的水平运动次数和垂直运动次数均高于氟西汀组和褪黑素组,有显著性差异(P<0.05)。2.采用Real time PCR检测各组大鼠松果体AANATmRNA、HIOMTmRNA表达情况,ELISA检测大鼠血清褪黑素(MT)含量,慢性应激能造成大鼠松果体AANATmRNA. HIOMTmRNA表达水平下降和血清MT含量的下降,氖西汀组、褪黑素组和脉冲电针组三种干预措施均可以逆转上述指标的下降,其中褪黑素组在改善大鼠松果体AANATmRNA、HIOMTmRNA表达方面优势明显,脉冲电针组大鼠松果体AANATmRNA、HIOMTmRNA表达均高于氟西汀组,有统计学意义(P<0.05,P<0.01)。3.免疫组化法观察各组大鼠主动脉组织中ET-1、eNOS阳性染色表达情况,酶联免疫法检测大鼠血清中ET含量,硝酸还原酶法检测大鼠血清NO含量,HE染色观察大鼠主动脉结构变化。①与空白对照组比较,模型组大鼠在主动脉有ET-1强阳性表达,同时模型组大鼠主动脉上几乎没有eNOS阳性表达,氟西汀组、褪黑素组和脉冲电针组大鼠主动脉均有ET-1弱阳性表达和eNOS阳性表达；与空白对照组比较,模型组大鼠主动脉ET-1阳性染色平均光密度上升、eNOS阳性染色平均光密度下降,均有显著性差异(P<0.01,P<0.01),脉冲电针组大鼠主动脉ET-1阳性染色平均光密度下降,与模型对照组有显著性差异(P<0.05),氟西汀组和褪黑素组eNOS阳性染色平均光密度上升,与模型对照组相比有显著性差异(P<0.05)；②慢性应激可以导致大鼠ET水平升高、NO水平降低,氟西汀组、褪黑素组和脉冲电针组三种干预措施均可以改变两指标的逆转；③大鼠主动脉HE染色显示,模型对照组大鼠胸主动脉有形态学改变,主动脉中膜可见数层弹力膜和平滑肌细胞,平滑肌细胞排列紊乱、水肿、增生,多数细胞形态改变、内皮细胞轻微肿胀,褪黑素和脉冲电针可以改善这些病理变化,氟西汀加重这种病理变化。4.免疫组化法观察大鼠主动脉组织中ACE1、AngⅡ、ATlR阳性表达,酶联免疫法检测大鼠血清中活性肾素、AngⅡ含量,黄嘌呤氧化酶法测定SOD活力,硫代巴比妥酸检测大鼠血清MDA含量,①空白对照组大鼠主动脉内皮细胞ACE1、AngⅡ、ATlR有少量阳性表达,模型对照组大鼠主动脉内皮细胞较空白对照组均有ACE1、AngII、AT1R强阳性表达,褪黑素组大鼠主动脉组织ACE1、AngⅡ、ATlR呈阳性表达,氟西汀组和脉冲电针组大鼠主动脉组织ACE1、AngⅡ、ATlR呈弱阳性表达,与空白对照组相比,模型对照组大鼠主动脉组织ACE1、AngⅡ、ATlR阳性染色平均光密度明显升高,差异均具有显著性(P<0.01),氟西汀组和脉冲电针组大鼠主动脉组织ACE1、AngⅡ、ATlR阳性染色平均光密度均有下降,且有显著性差异(P<0.05),褪黑素组大鼠主动脉组织Ang II、AT1R阳性染色平均光密度均有下降趋势,但与模型对照组无显著性差异(P>0.05),脉冲电针组大鼠主动脉组织ACE1、AngⅡ、AT1R阳性染色平均光密度较氟西汀组和褪黑素组有明显下降,且有显著性差异(P<0.05)。②与空白对照组比较,模型对照组大鼠血清中活性肾素和Ang II含量均升高,有显著性差异(P<0.01),氟西汀和脉冲电针均可以改善两指标的上升趋势,均有显著性差(P<0.01)；③与空白对照组比较,模型对照组大鼠血清中MDA水平显著升高、SOD活力显著下降,有显著性差异(P<0.01,P<0.01),三种干预措施均可以改善MDA水平上升和SOD活力下降的趋势,均有显著性差异(均为P<0.01)其中脉冲电针效果更有优势,褪黑素组MDA水平明显小于氟西汀组和脉冲电针组有显著性差(P<0.01)。结论1.慢性刺激21天后,通过行为学检测,模型组大鼠的探索行为、兴奋性、快感缺乏程度及对广泛事物的兴趣水平均低于空白对照组,说明抑郁模型复制成功；氟西汀组和脉冲电针组均可以改善慢性应激造成的抑郁大鼠行为学表现,其中脉冲电针对大鼠探索行为方面改善效果明显,表明电针在抗抑郁方面有很好的优势；褪黑素对抑郁大鼠行为学各指标有改善的趋势。2.慢性应激影响到大鼠松果体AANATmRNA、HIOMTmRNA基因表达,导致MT合成的减少,氟西汀组、褪黑素组和脉冲电针组三种干预措施均可以增加松果体AANATmRNA、HIOMTmRNA基因表达和MT合成,其中在改善血清MT方面,三种干预措施作用相当,在调控松果体AANATmRNA、HIOMTmRNA基因表达上升方面,褪黑素效果最强,其次为脉冲电针。3.慢性应激可以导致大鼠血管内皮细胞功能和结构损伤,诱发血管内皮功能障碍,褪黑素和脉冲电针对慢性应激大鼠胸主动脉结构损伤有改善作用；氟西汀有加重主动脉结构病理变化的趋势。4.抑郁模型大鼠RAS过度激活,同时机体出现氧化应激状态,氟西汀和电针均可以改善大鼠RAS过度激活以及机体内的氧化应激状态,其中电针在改善大鼠血清活性肾素、AngⅡ以及大鼠主动脉组织AngⅡ、ACE1阳性表达方面优势明显,褪黑素在改善大鼠机体氧化应激方面优势明显。5.鉴于实验数据,慢性应激可以引起大鼠机体RAS过度激活,长期持续的AngⅡ水平升高进而与AT1R结合,通过多种途径诱发自氧化,机体氧化-抗氧化系统平衡失调,引起血管内皮结构与功能损伤,同时由于机体MT含量的减少,机体自身的抗氧化能力减弱,进一步加深了血管内皮结构与功能损伤。抗抑郁治疗可以改善机负性情绪,调整RAS过度激活,减少氧化应激状态,从而减少对内皮功能及结构的损伤。MT含量的增加可以改善抑郁症机体氧化应激损伤和血管内皮损伤,对机体发挥保护作用,电针可能通过多靶向作用对机体起到调节作用。更多还原

【Abstract】 ObjectiveOver several decades, more evidence have emerged to suggest that depression disorder is a risk factor for Cardiovascular disease, Pathological mechanisms are not clear, some researcher show that vascular endothelial cells play an important role in depression and heart disease, it is reported that endothelial dysfunction is found in the presence of depression, there is little experimental study to support this point. The effects of depression on vascular endothelialendothelial will be the centre in this experimental study.Meantime, elevated levels of Ang II is happened in the patients with depression, oxidative stress was founded in central and peripheral of these patient, we suppose that depression disorder injure vascular endothelial through the overactive of renin-angiotensin system (RAS) and induce Oxidative Stress, and relatively experimental studies will be tested and verified.The low level of melatonin(MT) in patient body of depression is verified, the main research point of MT is the relationship between depression and sleep, antioxidant effects of MT are not studied in patient of depression, as The strongest effect scavengers of free radical, whether the decline of MT in depression patience will affect the balance between oxidative stress and anti-oxidative stress, and cause other physical illness, literature has not been reported, these question will be studied in this paper.Acupuncture, as a multi-target and multi-angle treatment of the disease, the effectiveness of acupuncture to depression has been demonstrated in clinical and experimental studied, meanwhile, more evidence are reported that acupuncture can adjust the RAS and endothelial function, but those effectiveness is not reported in the patient of depression in the literature, in this study, the effect of Three kinds of interventions (antidepressants, anti-oxidative stress and electro-acupuncture) will be observed in RAS, oxidative stress and endothelial function of depression model rats, and discuss the relationship between depression and vascular endothelial cell function.Method and Result1. The method of chronic unpredictable mild stress was utilized for replication rats as a model of depression, using open-field test, weight test, sugar preference evaluates the model of depression. After21days of stimulation, the model control group of rats was less than the control group in the test of open cross, open rear, weight gain and sugar preferences (P<0.01). This indicates the model of depression is made successfully, fluorine paroxetine and electro-acupuncture are all higher than model group in open cross and open rear preferences. EA group is better than fluorine paroxetine group and melatonin grou(p<0.05).2. Using Real time PCR detection the expression of AANATmRNA, HIOMTmRNA in pineal of rat, ELISA method show the content of melatonin in serum of rat, Three treatments all can raise the expression of AANATmRNA, HIOMTmRNA in pineal of rat and the content of melatonin in serum of rat, melatonin is the best way to improve the expression of f AANATmRNA, HIOMTmRNA in pineal of rat in three treatment.3. Using immunohistochemistry to show the ET-1and eNOS in Aortic tissue of rat. And Enzyme-linked immunosorbent assay show levels of ET in serum, nitrate reductase show the levels of NO in serum, three treatments all can stop the increasing ET-1and eternal, and stop the reducing of eNOS and NO. Electro-acupuncture is most effective on stopping the increasing of ET-1, fluorine paroxetine and melatonin are effective on improving the expression of eNOS. HE staining observe the changes of structure of the aorta, the aorta of model control group is modified, melatonin and electro-acupuncture can reduce those change, but fluorine paroxetine aggravate this pathological change.4. Using immunohistochemistry to show the ACE1, Ang Ⅱ, AT1R in Aortic tissue of rat, Enzyme-linked immunosorbent assay show levels of Active renin and Ang Ⅱ in serum, Xanthine oxidase show SOD, Thiobarbituric acid show the level of MDA, fluorine paroxetine and electro-acupuncture can stop the increasing of ACE1, Ang Ⅱ, AT1R in Aortic tissue of rat and decrease the levels of Active renin and Ang Ⅱ in serum, electro acupuncture is Superiority in reducing the level of Ang Ⅱ in serum and Aortic tissue of rat. Three treatments also can decrease the oxidative in the body of rats. Melatonin shows the best superiority in modifying the oxidative.Conclusion1. Behavior results suggest the successful modeling. Fluoxetine and electro acupuncture can improve behavioral performance. Electro acupuncture is better than the other two treatments in autonomous and exploratory movements.2. Chronic unpredictable mild stress combined the singly housed cause the low production of MT. Fluoxetine, Melatonin and electro acupuncture can be able to increase the production of MT. Melatonin shows the best superiority in it.3. Vascular endothelial function and structure are obviously damaged in depressed rats. Melatonin and electro acupuncture can all improve those pathological changes. Fluoxetine damage the structure of Aortic.4. Renin-angiotensin system was over-activated and oxidative stress status was strengthened. Fluoxetine and electro acupuncture can be all restraining over-activation of RAS and suppressing oxidative stress. Electro acupuncture is superior to other treatments in reducing over-activated of RAS. Nevertheless, Melatonin has better performance in suppressing oxidative stress.5. Given the experimental data, there are all changed in Renin-angiotensin system and oxidative stress, It is suggest that chronic stress may cause Renin-angiotensin system over-activate, Activation of the renin-angiotensin system leads to oxidative stress, and Vascular endothelial function and structure was damaged, meanwhile, Following the reduce of Melatonin in depressed body, and decrease of antioxidant ability of body. That aggravate the damage of vascular endothelial function and structure. Antidepressants, anti-oxidative stress and electro-acupuncture can all improve those pathology.更多还原