失血复合缺氧缺水缺食大鼠心脏损伤特点及其机制研究

发布时间：2018-04-28 12:28

本文选题：失血复合缺氧缺水缺食 + 心脏　；参考：《中国人民解放军军事医学科学院》2011年博士论文

【摘要】：目的和意义:由于爆炸恐怖袭击、人为劣质工程、地震灾害以及事故等可造成房屋建筑垮塌,人员被掩埋,掩埋在深层废墟内的人员受到失血及缺氧缺水缺食等的影响,将明显影响其生命体征和生命耐受力。心脏是对缺氧缺血较为敏感的器官之一,在失血复合缺氧缺水缺食条件下,心脏结构和功能的改变是影响甚至决定其生命耐受力的关键因素。关于失血复合缺氧缺水缺食对人员心脏的影响国内外报道极少。本研究立足于模拟灾难性掩埋条件,探讨失血复合缺氧缺水缺食大鼠心脏结构与功能的损伤规律、特点及其机制,其结果对于深埋人员的及时有效救治以及生命探测与监测仪的研制具有重要指导意义。材料与方法:采用本课题组设计并研制的生物医学实验常压低氧舱,调整舱内氧浓度为10%(误差0.1%),选用二级Wistar大鼠160只,随机分为正常对照组、单纯失血组、缺氧缺水缺食(三缺)组和失血复合缺氧缺水缺食(失血并三缺)组。大鼠于实验后1d、3d、5d和7d,采用生理、生化、常规病理、超微病理、分子病理、定量病理和免疫组织化学(SP)等多种技术方法,研究失血复合缺氧缺水缺食后心脏结构和功能改变及血清激素、细胞因子、心肌细胞凋亡相关因子在其中的作用机制。结果: (1)外周血血象变化:三缺组和失血并三缺组WBC数在3-7 d下降;RBC与Hb先下降后增高;提示发生血浓缩,雄性更为显著。 (2)血气指标变化:三缺组和失血并三缺组pO2、pCO2明显进行性下降,PH值3d后降低,雄性尤为显著。 (3)大鼠血清心肌酶谱的改变:单纯失血组血清LDH、CK明显降低,AST无明显变化;三缺组AST、LDH和CK均先降低后升高;失血并三缺组可加重LDH、CK的变化。 (4)血清电解质的变化:三缺组和失血并三缺组血清Na+、K+、Ca2+呈增高趋势。 (5)细胞因子的改变:三缺组和和失血并三缺组伤后大鼠血清IL-6先降低后增高,TNFα暂时性升高,IL-1变化较轻微。 (6)血浆激素的变化:三缺组和失血并三缺组伤后1d可致ACTH先升高后降低;7d时皮质醇明显升高,上述变化尤以失血并三缺组更为明显。 (7)大鼠心脏结构改变:单纯失血组和三缺组心脏的基本病变为心肌细胞变性、凋亡、坏死;肌纤维排列紊乱、断裂、溶解,线粒体肿胀、嵴消失,基质均质状;内质网扩张,脱颗粒;糖原颗粒减少;血管内皮细胞凋亡;病变于1d~7d呈进行性加重;当三缺复合失血时上述损伤明显加重。其病变具有速发性、进行性、全心性和部位差异性特点(左心重于右心,心室重于心房,内层重于中外层,心肌细胞重于蒲肯野细胞)。 (8)三种致伤组于各时间点心肌细胞凋亡指数改变:单纯失血组、三缺组和失血并三缺组心肌细胞凋亡指数于1d～7d均显著高于正常对照组(P0.05,P0.01),其中失血并三缺组于早期(1d)较其他两组最为明显;于3-7d增高幅度呈降低趋势,提示可能与心肌细胞坏死增多有关; (9)凋亡相关因子的改变:于各时间点Bax和Caspase-3表达均呈增强、MOD值增高趋势,其中失血并三缺组较失血组和三缺组于早期更为明显;Bcl-2均呈表达减弱、MOD值降低趋势,尤其5-7d时较明显;上述凋亡相关因子表达变化呈现失血并三缺组依次较三缺组、单纯失血组加重趋势。 (10)ERK信号转导通路相关因子的变化: p-CREB和RKIP于各时间点均基本呈不同程度增强、MOD值增高,其中失血并三缺组较失血组和三缺组于早期更为明显;p-ERK则均表达减弱、MOD值降低,尤其5-7d时较明显。上述(9)和(10)结果提示,凋亡相关因子变化及ERK信号转导通路相关因子异常均参与心肌细胞凋亡的发生发展过程。结论:在模拟掩埋条件下大鼠发生失血复合缺氧缺水缺食后:(1)心脏血清心肌酶谱等功能发生明显异常;(2)心肌组织学和超微结构发生严重损伤,心肌细胞凋亡指数显著增高;上述病变具有速发性、进行性、全心性和部位差异性特点;(3)心脏功能异常和心肌结构损伤重于和快于单纯失血和缺氧缺水缺食组;血清细胞因子和激素的异常参与其损伤的病理生理过程。(4)心肌细胞促凋亡因子Bax表达增加,抑凋亡因子Bcl-2表达减少相关,Bcl-2/Bax比值下降,表达失衡,并进一步通过线粒体途径,释放细胞色素C,激活Caspase-3,引发心肌细胞凋亡。(5)ERK信号转导通路相关基因表达异常(RKIP和p-CREB表达增加,p-ERK表达减少等),参与心肌细胞凋亡的发生发展过程。
[Abstract]:Objective and significance: due to the explosion of terrorist attacks, artificial poor engineering, earthquake disasters and accidents, people are buried in the buried, buried in the deep ruins of the blood loss and hypoxia, water shortage and lack of food, which will obviously affect their vital signs and life tolerance. The heart is more sensitive to hypoxia and ischemia. One of the organs, the changes in the structure and function of the heart are the key factors that affect or even determine their life tolerance under the condition of the complex anoxia and lack of water and lack of food. The influence of blood loss and lack of water and lack of food on the heart of the people is rarely reported. The damage laws, characteristics and mechanism of the heart structure and function of the rat are of great guiding significance for the timely and effective treatment of the deep buried personnel and the development of the life detection and monitoring apparatus.
Materials and methods: the oxygen concentration in the normal pressure hypoxic chamber designed and developed by our group was 10% (0.1%), and 160 rats of grade two Wistar rats were selected and randomly divided into normal control group, simple blood loss group, anoxia and water deficiency (San Que) group and blood loss and lack of water and lack of food (blood loss and three deficiency) in the group. After 1D, 3D, 5D and 7d, a variety of technical methods, such as physiological, biochemical, pathological, ultrapathological, molecular pathology, molecular pathology, quantitative pathology and immunohistochemistry (SP), were used to study the changes of cardiac structure and function and the mechanism of serum hormone, cytokine and cardiomyocyte apoptosis related factors after blood loss complex anoxia and lack of water and lack of food.
Result:
(1) peripheral blood hemogram changes: three the number of WBC in the deficient group and the group with blood loss and three deficiency decreased at 3-7 D; RBC and Hb first decreased and then increased; suggesting that blood concentration is more significant for males.
(2) changes in blood gas index: three in group pO2 and pCO2 in group three and three respectively.
(3) the change of serum myocardial enzyme spectrum in rats: the serum LDH, CK decreased obviously in the simple blood loss group, and there was no obvious change in AST. Three the deficiency group was AST, LDH and CK decreased first, and the loss of blood and three deficiency could aggravate the changes of LDH and CK.
(4) changes in serum electrolytes: three, serum Na+, K+ and Ca2+ increased in the absence group and the three group with blood loss.
(5) cytokine changes: three in the absence group, and three in the group with blood loss and three deficiency, the serum IL-6 decreased first and then increased, while TNF alpha increased temporarily, and the change of the serum level was slight.
(6) changes in plasma hormone: three deficiency group and loss of blood and three deficiency group, 1D can cause ACTH to increase first and then decrease, and the cortisol increases obviously at 7d, especially in the group of hemorrhagic and three deficiency.
(7) changes in the cardiac structure of rats: the basic pathological changes in the heart of the pure blood loss group and the three deficiency group were the degeneration, apoptosis and necrosis of the cardiac myocytes, the disorder of the muscle fibers, the breakage, dissolution, the swelling of mitochondria, the disappearance of the crista, the homogenization of the matrix, the endoplasmic reticulum dilation, degranulation, the decrease of glycogen granules, the apoptosis of the vascular endothelial cells, and the progressive aggravation of the 1d~7d; when three; when lesion was progressively aggravated in the vascular endothelial cells; when three, when the lesion was progressively aggravated; when three, when the lesion was progressively aggravated; when the lesion was aggravated; when three was aggravated; when the lesion was aggravated; when the lesion was aggravated; when three became aggravated; when the lesion was aggravated; when three aggravated; when the lesion was progressively aggravated; when three, when the lesion was progressively aggravated; when three, when the lesion was aggravated; when three became progressively aggravated; when the lesion was aggravated The damage of these injuries is obviously aggravated. The lesion has the characteristics of rapid onset, progressive, full heart and site difference (left heart is heavier than right heart, ventricle weighs the atrium, inner layer is heavier than Chinese and foreign layer, and cardiac myocytes are heavier than the Purkinje cells).
(8) the change of apoptotic index of cardiac myocytes at all time in three kinds of injury groups: pure blood loss group, three deficiency group and three deficiency group of 1D ~ 7d were significantly higher than that of normal control group (P0.05, P0.01), among which, blood loss and three deficiency group were most obvious in the early stage (1D) than those in the other two groups, and the increase of 3-7d was decreasing. It can be related to the increase of necrosis of cardiac myocytes.
(9) the changes of apoptosis related factors: the expression of Bax and Caspase-3 increased at all time points, and the MOD value increased, in which the loss of blood and the three deficiency group were more obvious than those in the early stage of the loss group and the three deficiency group; the expression of Bcl-2 decreased and the MOD value decreased, especially in 5-7d; the expression of apoptosis related factors presented in the group of hemorrhagic and three deficiency groups. In the less than three group, the simple blood loss group aggravated the trend.
(10) the changes of ERK signal transduction pathway related factors: p-CREB and RKIP were basically enhanced at various time points, and the value of MOD increased, in which the blood loss and the three deficiency group were more obvious than those in the bleeding group and the three group at the early stage, and the p-ERK expression decreased and the MOD value decreased, especially when 5-7d was more obvious.
The above (9) and (10) results suggest that changes in apoptosis related factors and abnormalities in ERK signal transduction pathway related factors are involved in the occurrence and development of cardiomyocyte apoptosis.
Conclusion: under the simulated burial condition, the rat blood loss complex anoxia and lack of water and lack of food: (1) the cardiac serum myocardial enzyme spectrum and other functions were obviously abnormal; (2) the myocardial histology and ultrastructure were seriously damaged and the apoptosis index of myocardial cells increased significantly; the above pathological changes have the characteristics of rapid onset, progressive, whole heart and location difference; (3) heart The abnormality of the dysfunction of the organs and the damage of the myocardial structure were more important than that of the simple loss of blood and anoxia and lack of water, and the abnormalities of serum cytokines and hormones involved in the pathophysiological process of the injury. (4) the expression of apoptosis factor Bax increased, the expression of anti apoptotic factor Bcl-2 decreased, the ratio of Bcl-2/Bax decreased, the expression was unbalance, and further passed through Mitochondrial pathway, release cytochrome C, activate Caspase-3 and induce cardiomyocyte apoptosis. (5) abnormal expression of ERK signal transduction pathway related gene expression (RKIP and p-CREB expression increase, p-ERK expression decrease, etc.), and participate in the development and development of cardiomyocyte apoptosis.

【学位授予单位】：中国人民解放军军事医学科学院
【学位级别】：博士
【学位授予年份】：2011
【分类号】：R363

【参考文献】