急进高原环境对大鼠心肌损伤作用及药物保护机制研究

发布时间：2018-01-16 06:19

本文关键词：急进高原环境对大鼠心肌损伤作用及药物保护机制研究　出处：《兰州大学》2014年硕士论文　论文类型：学位论文

【摘要】：目的 1.以55m、1500m、2260m、3400m、4300m五个海拔进行梯度实验,研究大鼠急进高原环境后心肌的受损情况及趋势,探讨氧化应激与线粒体在心肌损伤中的作用； 2.以氧化应激、生化、血气、形态显微观察等指标综合评价四种药物干预后,对急进高原大鼠心肌的影响,筛选出效果优良的药物； 3.探索药物美托洛尔保护急进高原大鼠心肌过氧化损伤与线粒体损伤的机制。方法实验一：大鼠随机分为5组每组12只,A组(上海55m)、B组(甘肃兰州1500m)、C组(青海西宁2260m)、D组(甘肃碌曲3400m)、E组(青海玛多4300m),记录体重后分别从平原地区(上海55m)急进实地海拔各组处。3d后取静脉血清测定生化全项,动脉血测血气等指标,心肌组织固定做病理、电镜观察及液氮冷冻做氧化水平测定；实验二：急进3400m后分别给予四种药物：胺腆酮、美托洛尔、卡托普利、呋噻米及阳性对照药物地塞米松。记录1d及3d体重,3d后给药组大鼠的心率、血压,并采眼眶静脉血,用于生化项目检测(血清CK、CK-MB、AST、HDBH、LDH等)及心肌标志物测定(MYO、Tn-I);所有实验动物麻醉后腹主动脉采集动脉血进行血气分析(ph、pO2、pCO2、Hct、ctHb、 cHCO3、BB、 BE、SO2等)；活体取大鼠心脏组织记录重量,切取部分固定进行病理及电镜观察；剩余心肌组织用液氮进行快速冷冻保存,用于测定氧化水平(SOD、MDA、NO);实验三：平原组、海拔3400m空白组及美托洛尔组取心脏匀浆进行线粒体复合体(COM-Ⅰ、 COM-Ⅱ、COM-Ⅲ、COM-Ⅳ)活性,MDH. SDH及ATP活性测定。结果 1.实验一各组大鼠心肌酶谱结果B、C、D、E组大鼠较A组明显增加,其中CK及CK-MB在B组分别增加了43.87%、55.36%,C组增加了185.14%、84.54%,D组增加了73.54%、139.46%,E组增加了118.28%、175.32%(P0.05)。因此B组(1500m)、C组(2260m)、D组(3400m)、E组(4300m)心肌酶谱在血液中的释放明显增加;各组大鼠心肌标志物结果：与A组相比MYO、Tn-I在C、D、E组均显著增加,其中C组增加了182.82%、21.30%,D组增加了328.35%、54.73%,E组增加了444.04%、62.67%(P0.05),标志物结果显示了在C组(2260m)、D组(3400m)、E组(4300m)的心肌损伤较平原组明显增加； 2.实验一与A组相比各组大鼠氧化应激指标显示,SOD在B、C、D、E组分别减少10.06%、13.51%、12.18%、29.92%；MDA在B、C、D、E组分别增加14.67%、89.33%、36.01%、86.66%；NO在B、C、D、E组分别减少64.45%、65.49%、66.94%、40.54%(P0.05),提示在C、D、E组大鼠心肌氧化应激水平增加,动脉氧分压降低明显； 3.实验一大鼠动脉氧分压及二氧化碳分压明显降低(P0.05)(海拔≥2260m),与A组相比,pCO2在B、C、D、E分别下降9.56%、6.68%、25.07%、32.01%；pO2在B、C、D、E分别下降7.95%、11.97%、48.94%、43.09%；s02在D、E组明显下降分别下降12.04%、8.25%(P0.05); 4.实验二,在3400m海拔处应用药物后对过氧化损伤均有不同改善作用,其中美托洛尔组SOD及NO较高原空白组分别增加10.75%、144.65%(P0.05),MDA减少25.49%(P0.05),并且提高氧分压使之增加31.68%(P0.05),能明显降低心肌酶谱增加的情况； 5.实验三,在3400m海拔处线粒体复合体Ⅰ、Ⅱ、Ⅲ、Ⅳ的活性在高原模型组较平原组明显下降,其中COM-Ⅰ、COM-Ⅱ、COM-III下降显著,与平原组相比在高原地区COM-Ⅰ下降了26.17%,COM-Ⅱ下降了24.21%,COM-Ⅲ下降了17.94%,COM-IV下降了32.61%(P0.05),应用药物美托洛尔后明显提高其活力,分别较高原组上升22.48%、44.01%、36.01%、17.23%(P0.05),同样ATP各含量在应用药物后明显增加(P0.05)； 6.实验一及实验二的心肌组织病理及电镜结果显示,海拔≥2260m损伤较平原组显著,呈现肌纤维的不整齐排列,线粒体肿胀溶解,闰盘加宽等,给予药物后有不同程度的改善,其中美托洛尔保护作用较明显。结论 1.实验动物从平原55m急进1500m、2260m、3400m、4300m不同海拔后,氧化应激结果显示高原环境下氧自由基的增加所带来的负面影响显示心肌受损程度明显并随着海拔升高有升高趋势,并且在海拔≥2260m处显著增加；大鼠动脉血氧分压,二氧化碳分压,BE及HC03降低,指示在海拔≥2260m大鼠具有代偿性的呼吸性碱中毒或代谢性酸中毒,并随着海拔升高有加重趋势。 2.对心血管系统的药物进行评价发现,在抵抗氧化损伤方面均有效,而各药物的生化血气结果却各不相同,其中美托洛尔在保护心脏氧化损伤及提高动脉血氧饱合度等方面有良好的效果； 3.急进高原3400m后心肌线粒体呼吸链各复合体活性下降,使ROS产生增加,并且主要产生ROS部位在线粒体复合体Ⅰ、Ⅱ、Ⅲ。心肌组织氧化应激与线粒体复合体活性的相关性分析,发现急进高原后氧化应激损伤程度与线粒体复合体有显著负相关性,因此分析线粒体复合体活性的下降是导致心肌组织氧化应激损伤的主要原因,在应用药物美托洛尔后能通过提高线粒体复合体活性来降低ROS所带来的急性高海拔损伤。
[Abstract]:objective
1. to 55m, 1500m, 2260m, 3400m, 4300m five altitude gradient experiment, damage situation and trend of the research on high altitude environment after myocardial in rats, to investigate the effects of oxidative stress and mitochondria in myocardial injury;
2. in oxidative stress, blood biochemical, morphological, microscopic observation and comprehensive evaluation indexes of four kinds of drug intervention effects on myocardial in rats at high altitude, the excellent effect of drug screening;
3. to explore the drug metoprolol myocardial protection at high altitude rats mechanism of oxidative damage and mitochondrial damage.
Method
Experiment one: the rats were randomly divided into 5 groups with 12 rats in each group, group A (Shanghai 55m), group B (Gansu Lanzhou 1500m), group C (Qinghai Xining 2260m), D group (group E, 3400m Gansu Luqu) (Qinghai 4300m, record the weight after Maduo) respectively from the Plains (Shanghai 55m) determination of biochemical radical groups at.3d altitude field of venous serum, measured arterial blood gas indexes, myocardial tissue fixed pathology, electron microscope observation and determination of the oxidation level for liquid nitrogen refrigeration; experiment two: radical 3400m after the four drugs were given: Amiodarone, metoprolol, Cato Plymouth, furosemide and positive the control of dexamethasone. Recorded 1D and 3D weight, 3D after the administration of rats, heart rate, blood pressure, and the orbital venous blood for biochemical tests (serum CK, CK-MB, AST, HDBH, LDH etc.) and cardiac markers (MYO, Tn-I); the experimental animal after anesthesia in abdominal aorta arterial blood gas Analysis (pH, pO2, pCO2, Hct, ctHb, cHCO3, BB, BE, SO2); record the weight of living donor rat heart tissue, cut a part fixed for pathological and electron microscopic observation; the remaining myocardial tissue using liquid nitrogen rapid freezing preservation, for the determination of the oxidation level (SOD, MDA, NO); experiment three: the plain group, the elevation of 3400m blank group and metoprolol group. Heart homogenate of mitochondrial complex (COM- I, COM- II, COM- III, COM- and IV) activity, determination of MDH. SDH and ATP activity.
Result
The first 1. groups of myocardial enzymogram of rats results in B, C, D, E group rats were significantly increased compared with group A, CK and CK-MB in B group were increased by 43.87%, 55.36%, C increased 185.14%, 84.54%, D increased 73.54%, 139.46%, E group increased 118.28% (175.32% P0.05). So the B group (1500m), C group (2260m), D group (3400m), E group (4300m) of myocardial enzymes in the blood release increased significantly; the rats cardiac biomarker results: compared with A group MYO, Tn-I in C, D, E were significantly increased. In the C group increased by 182.82%, 21.30%, D group increased by 328.35%, 54.73%, E increased 444.04%, 62.67% (P0.05), marker results show that in the C group (2260m), D group (3400m), E group (4300m) myocardial injury obviously increased compared with the plain group;
Experiment 2. compared with the A group rats showed oxidative stress in B, SOD, C, D, E were reduced by 10.06%, 13.51%, 12.18%, 29.92%; MDA in B, C, D, E group respectively increased 14.67%, 89.33%, 36.01%, 86.66%; NO in B, C, D, E groups were reduced by 64.45%, 65.49%, 66.94%, 40.54% (P0.05), C D, E in rats, myocardial oxidative stress increased, arterial oxygen pressure decreased significantly;
3. of the rat PaO2 and PaCO2 decreased significantly (P0.05) (at an altitude of more than 2260m), compared with the A group, pCO2 in B, C, D, E were 9.56%, 6.68%, 25.07%, 32.01%; pO2 in B, C, D, E were 7.95%, 11.97%, 48.94% 43.09%, S02; in D, E group were decreased respectively decreased by 12.04%, 8.25% (P0.05);
4. experiment two, on oxidative damage in different altitude effect in 3400m application of drugs, including SOD and NO compared with metoprolol group plateau blank group were increased by 10.75%, 144.65% (P0.05), MDA (P0.05), reduced by 25.49% and increase the oxygen partial pressure increased 31.68% (P0.05), can significantly reduce the spectrum increase the myocardial enzyme;
5. experiment three, at an elevation of 3400m at the mitochondrial complex I, II, III, IV activity in model group was significantly higher than that in plain plateau group decreased, the COM- I and COM- II, COM-III decreased significantly, compared with the plain group in the plateau region COM- I decreased by 26.17%, COM- decreased by 24.21% COM- II, III decreased by 17.94% COM-IV, down 32.61% (P0.05), improve the activity of drug use of metoprolol, respectively compared with the plateau group increased by 22.48%, 44.01%, 36.01%, 17.23% (P0.05), as ATP content increased significantly after the drug application (P0.05);
Experiment 6. and experiment two myocardial histopathology and electron microscopy results show that the altitude of more than 2260m compared with the plain group showed significant damage, muscle fiber is not neatly arranged, mitochondrial swelling and dissolution, intercalated disc broadening, giving drugs have different degrees of improvement, the protective effect of metoprolol was obvious.
conclusion
1. experimental animal from the plain 55m 1500m 2260m, 3400m radical, 4300m, different altitude, oxidative stress results showed that the negative influence brought by the increase of oxygen free radicals in plateau environment showed the degree of myocardial damage and significantly increased with the increase of elevation, and significantly increased at an altitude of more than 2260m; rat arterial oxygen partial pressure, the partial pressure of carbon dioxide, BE and HC03 decreased, indicating a compensatory elevation of more than 2260m in rats with respiratory alkalosis and metabolic acidosis, and with the increase of elevation has aggravated the trend.
The 2. drugs on the cardiovascular system evaluation found that are effective in resisting oxidative damage, and the blood biochemical drugs but the results are not the same, in which Mei TORO M has a good effect on the protection of cardiac oxidative damage and improve arterial oxygen saturation;
Decreased myocardial mitochondrial respiratory chain complex activity of each 3. at high altitude after 3400m, the increased production of ROS, and mainly ROS sites in the mitochondrial complex I, II, III. Correlation analysis of myocardial oxidative stress and mitochondrial complex activity, found at high altitude after oxygen had a significant negative correlation of the stress and the degree of damage of mitochondrial complex, therefore decreased analysis of mitochondrial complex activity is a major cause of oxidative stress in myocardial tissue injury, can reduce the acute high altitude ROS damage brought by increasing the activity of mitochondrial complex application in drug metoprolol.

【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R594.3

【参考文献】