氧自由基对急性脑死亡心脏供体影响的实验研究

发布时间：2018-03-27 22:11

本文选题：急性脑死亡　切入点：心肌损伤　出处：《昆明医科大学》2014年硕士论文

【摘要】：目的：本研究旨在通过快速颅内加压法建立猪急性脑死亡模型并在无药物干预情况下观察猪脑死亡和非脑死亡血清中超氧化物歧化酶(SOD)、丙二醛(MDA)、白介素6(IL-6)、单核细胞趋化蛋白1(MCP-1)等含量的变化。心肌组织检查超氧化物歧化酶(SOD) mRNA的表达。心肌病理切片观察心肌细胞的变化,对心率,脑电图、颅内压、平均动脉压进行评估,并探讨氧自由基对猪急性脑死亡心脏供体的影响。方法：6头健康版纳小耳猪随机分为2组(n=3),实验组(A组)和对照组(B组),。实验组静脉全身麻醉后行气管切开插管,呼吸机辅助呼吸,膀胱造瘘、颈内动静脉插管、在右侧颅骨矢状线外侧0.2—0.5cm处和左侧颅骨矢状线与冠装线交界部的外上2/3,距离矢状线0.2cm处各钻一个直径约lcm的孔,一根Foley18F气囊导尿管由右侧孔置入硬脑膜下腔内,向左侧气囊导尿管中以2m1/s注入25—40m1生理盐水,逐渐膨胀气囊,增加颅内压,注水时间在1分钟内,Foley气囊导管加压建立急性脑死亡模型并维持10h,左侧将颅内压传感导线沿钻孔进入硬脑膜下腔,记录和观察脑死亡前后颅内压变化。对照组行静脉全身麻醉和气管插管,膀胱造瘘、颈内动静脉插管后给予0.9%生理盐水和麻醉药物维持。实验组在建立急性脑死亡模型后,应用0.9%生理盐水和多巴胺维持CVP为5-10cmH2O, MAP为60mmHg-90mmHg。若发生尿崩症应用抗利尿激素,所用药量、时间及尿量详细记录。实验组和对照组实验过程中其他都相同,但只有实验组建立急性脑死亡模型。应用快速颅内加压法建立脑死亡模型,通过呼吸、循环支持维持实验动物脑死亡状态10小时,10小时后撤除呼吸、循环支持。A B两组实验动物分别在0.5h、2h、4h、6h、8h、10h内取动脉血6ml检测血清超氧化物歧化酶、丙二醛、白介素6、单核细胞趋化蛋白1的含量。在脑死亡0.5h、2h、4h、6h、8h、10h检测心率、心电图、脑电图、平均动脉压,实验末期取左心室心肌组织2块各约1.0g分别保存备用。结果： 1.在通过快速颅内加压法建立猪脑死亡模型中,6头猪手术成100%,术后10h模型成活率90%,造模型过程中死亡1头,5头猪用于课题研究。失败原因在实验过程中频发室颤抢救无效死亡。 2.血流动力学和强心药物的用量：实验组在通过快速颅内加压法建立猪脑死亡模型后,后期随着心功能的逐渐下降,平均动脉压(MAP)降低,中心静脉压(CVP)升高,呈低血压状态,需用血管活性药物多巴胺才能维持基础血压。实验组在猪脑死亡模型建立后,多巴胺用量比对照组明显增多,脑死亡状态心率较对照明显减慢。 3血清SOD活性变化：实验组较对照组血清SOD水平增高。实验组和对照组血清SOD水平变化在0.5h、6h、8h具有显著性差异(P0.05)。 4血清MDA含量变化：实验组较对照组血清MDA含量增高。实验组和对照组血清MDA含量变化在8h、10h具有显著差异(P0.05)。 5血清IL-6活性变化：实验组与对照组在10h高于对照组。实验组和对照组血清IL-6活性变化具有显著差异(P0.05)。 6血清MCP-1活性变化：实验组与对照组在10h高于对照组。两组MCP-1存在显著差异(P0.05)。 7心肌SODmRNA表达：实验组SOD1和SOD2明显高于对照组,实验组和对照组SODmRNA表达具有显著差异(P0.05)。 8心肌组织光镜下观察：实验组心肌间质水肿,部分心肌纤维颗粒变性,心肌间质血管呈收缩状态,肌纤维水样变性,炎细胞浸润,肌纤维断裂。对照组心肌纤维排列整齐,横纹清晰。实验组与对照组具有显著差异。结论： 1.应用快速颅内加压法建立猪脑死亡模型,比较符合临床脑死亡的发展过程,经有效的呼吸和循环支持,急性脑死亡状态可稳定维持。 2.心功能下降是脑死亡后心脏重要的病理生理特征,急性脑死亡可导致猪心肌组织损伤,并可出现心肌细胞形态学改变。 3.运用脑电图和颅内压检测能够增加对急性脑死亡判定的准确性。 4.急性脑死亡后MDA和IL-6MCP-1的生成增加,SOD能够清除氧自由基并减少生物膜的脂质过氧化和炎症因子的生成。 5.急性脑死亡过程中心肌SODmRNA高度表达,表明急性脑死亡状态下心肌存在自我抗氧化功能。
[Abstract]:Objective : To study the changes of superoxide dismutase ( SOD ) , malondialdehyde ( MDA ) , interleukin - 6 ( IL - 6 ) and monocyte chemoattractant protein 1 ( MCP - 1 ) in swine with acute brain death by rapid intracranial pressure method .

Methods : Six healthy volunteers were randomly divided into 2 groups ( n = 3 ) , experimental group ( group A ) and control group ( group B ) . In the experimental group , 0 . 9 % normal saline and 0 . 9 % saline were injected into the lower cavity of the left cranial base . The results were as follows : 1 minute , 2 h , 4 h , 6 h , 8 h , 10 h .

Results :

1 . In the swine brain death model established by rapid intracranial pressure method , 6 pigs were operated at 100 % , the survival rate of 10 hours after operation was 90 % , 1 head was died in the model process and 5 pigs were used for the subject research .

2 . The blood flow dynamics and the dosage of cardiotonic medicine : The experimental group , after establishing the porcine brain death model by rapid intracranial pressure method , decreased the average arterial pressure ( MAP ) and the central venous pressure ( CVP ) in the later stage .

The serum SOD activity of the experimental group was higher than that in the control group . The changes of serum SOD level in the experimental group and the control group were significantly different at 0.5h , 6h and 8h ( P0.05 ) .

The content of MDA in serum of the experimental group was higher than that in the control group , and the content of MDA in the experimental group and the control group was significantly higher than that in the control group ( P0.05 ) .

Serum IL - 6 activity in experimental group and control group were significantly higher than those in control group ( P0.05 ) .

Serum MCP - 1 activity was significantly different between the experimental group and the control group ( P < 0.05 ) .

7 . SODmRNA expression in myocardium : SOD1 and SOD2 in experimental group were significantly higher than those in control group , and the expression of SODmRNA in experimental group and control group was significantly different ( P0.05 ) .

Under the microscope of myocardial tissue , the myocardial interstitial edema , partial cardiac muscle fiber granule degeneration , myocardial interstitial vessels were contracted , myofiber water - like degeneration , inflammatory cell infiltration and muscle fiber breakage were observed in the experimental group .

Conclusion :

1 . The swine brain death model was established by rapid intracranial pressure method , and the development process of clinical brain death was compared with that of clinical brain death , and the acute brain death status could be maintained stably through effective breathing and circulatory support .

2 . The decline of cardiac function is an important pathological characteristic of heart after brain death , and acute brain death can lead to injury of myocardial tissue of pig , and the morphological change of myocardial cells can occur .

3 . The accuracy of determination of acute brain death can be increased by using EEG and ICP .

4 . The production of MDA and IL - 6MCP - 1 increased after acute brain death , and SOD was able to scavenge oxygen free radicals and reduce lipid peroxidation and inflammatory factors .

5 . The expression of SODmRNA in the myocardium during acute brain death indicates that there is a self - oxidation function in the myocardium in the state of acute brain death .

【学位授予单位】：昆明医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R654.2

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