糖尿病大鼠痛觉减退与心肌缺血再灌注损伤易损性增加的相关性研究

发布时间：2018-06-07 08:03

本文选题：糖尿病神经病变 + 心肌缺血再灌注　；参考：《山西医科大学》2017年硕士论文

【摘要】：目的:通过分析降钙素基因相关肽(CGRP)、P物质(SP)在心肌,背根神经节及血清的表达变化与糖尿病大鼠痛觉减退、心肌易损性增加的关系,探讨痛觉减退与糖尿病大鼠心肌缺血再灌注损伤易损性增加的相关性。方法:1、Ⅰ型糖尿病大鼠模型的建立:200-250g雄性SD大鼠60只,腹腔注射链脲佐菌素(streptozocin,STZ,50mg/kg)作为糖尿病组(DM组)。将注射STZ后一周内血糖持续16.7mmol/L为糖尿病造模成功标准;同时喂养30只同周龄的正常大鼠作为对照,每周测量体重、血糖值、热痛甩尾潜伏期(tail flick latency,TFL);注射STZ第五周末采用ELISA法测定两组大鼠血甘油三酯值并比较分析。2、测量甩尾潜伏期及糖尿病分组:根据注射STZ后第5周末测得TFL值是否大于注射STZ前对照值的2倍,将糖尿病大鼠进一步分为DM1组(TFL对照值x 2)和DM2组(TFL对照值x 2)。3、测量、分析两组糖尿病大鼠CGRP、SP变化:采用免疫荧光技术和和ELISA法测定心肌、上胸段(T1-5)和腰骶背根神经节(DRG)及血清CGRP,SP的含量:并观察其在心肌处的含量分布。分析DM1组和DM2组上述测量值差异。4、心肌梗死面积及心肌细胞凋亡的分析:采用TTC染色法、TUNEL分析凋亡试剂盒测定分析心肌梗死面积及心肌细胞凋亡程度,并分析DM1组和DM2组上述测量值差异。5、测量、分析糖尿病大鼠神经生长因子(NGF)及辣椒素受体(TRPV1):采用ELISA法和western blot法分别定量分析缺血心肌NGF及TRPV1的表达变化。结果:1、糖尿病组大鼠造模五周后,与对照组相比,体重发生显著降低降低(P0.01),而血糖在造模早期即升高至糖尿病水平(24h后),且甘油三酯亦出现显著升高。2、糖尿病组大鼠甩尾潜伏期逐渐延长,至5w时有显著性差异。与对照组相比,DM组的CGRP、SP在心肌、背根神经节及血清处的含量均显著下降(P0.05),且DM2组中CGRP、SP含量显著低于DM1组水平(P0.05)。3、与I/R组正常大鼠相比,I/R组糖尿病大鼠心肌梗死面积显著增加、心肌细胞凋亡比率均显著升高(P0.05);DM组中,DM2组大鼠心肌缺血再灌注后,各项心肌损伤指标均显著高于DM1组。与相应的假手术组比较,I/R组正常大鼠CGRP,SP显著升高,I/R组糖尿病大鼠CGRP,SP升高不显著。4、与相应的假手术组比较,正常大鼠I/R组缺血心肌处TRPV1表达显著升高(P0.05),糖尿病I/R组TRPV1表达变化不显著,并且显著低于非糖尿病组(P0.05),且DM1组和DM2组相比,缺血心肌处TRPV1表达无显著差异。各组NGF含量变化:与相应的假手术组比较,正常I/R组背根神经节、缺血心肌及血清表达显著升高(P0.05),糖尿病I/R组NGF表达变化不显著;与对照组相比,DM1组NGF含量显著升高(P均0.05),而DM2组NGF含量显著下降(P0.05)。结论:1、糖尿病组大鼠在注射STZ后痛觉逐渐减退,表现为甩尾潜伏期持续升高,而正常组大鼠甩尾潜伏期无显著改变;糖尿病大鼠个体甩尾潜伏期变化率不同,反映其外周和内脏感觉神经病变程度不同,并且与感觉神经CGRP,SP显著降低程度相关。2、甩尾潜伏期变化率较高的DM组大鼠(DM2组)对心肌缺血再灌注损伤更敏感,推断这可能与DM2组CGRP,SP含量与DM1组相比显著下降有关。3、糖尿病大鼠NGF和TRPV1的变化可能与感觉神经病变及CGRP、SP含量变化有关。
[Abstract]:Objective: To investigate the relationship between the changes of the expression of calcitonin gene related peptide (CGRP), substance P (SP) in the myocardium, the dorsal root ganglion and serum, the relationship between the decrease of pain and the increase of myocardial vulnerability in diabetic rats, and to explore the correlation between the decrease of pain and the increase of vulnerability of myocardial ischemia reperfusion injury in diabetic rats. Methods: 1, model type I diabetic rat model Establishment: 60 200-250g male SD rats, intraperitoneal injection of streptozotocin (streptozocin, STZ, 50mg/kg) as diabetic group (group DM). The blood glucose sustained 16.7mmol/L in the week after STZ was used as a successful standard for diabetes modeling. At the same time, 30 normal rats of the same age were fed as control, and the weight, blood sugar, and tail flick incubation period were measured weekly. Tail flick latency, TFL); the blood triglyceride value of two groups of rats was measured by ELISA method at the end of the injection of STZ and the.2 was compared and analyzed, and the latency of tail flick and diabetes group were measured. The diabetic rats were further divided into DM1 group (TFL control 2) and 2 groups according to whether the TFL values were more than 2 times of the control value before the injection of STZ fifth weekend after the injection of STZ. (TFL control value x 2).3, measurement and analysis of CGRP, SP changes in two groups of diabetic rats: Determination of myocardium by immunofluorescence and ELISA and the content of CGRP and SP in the upper thoracic segment (T1-5) and the lumbosacral dorsal root ganglion (DRG) and serum, and to observe the distribution of its content in the myocardium. The analysis of myocyte apoptosis: TTC staining and TUNEL analysis of apoptosis kits were used to determine the area of myocardial infarction and the degree of myocardial apoptosis, and the difference between the DM1 group and the DM2 group was analyzed. The measurement and analysis of the neural growth factor (NGF) and capsaicin receptor (TRPV1) in diabetic rats were measured by ELISA and Western blot respectively. The changes in the expression of NGF and TRPV1 in the ischemic myocardium were analyzed. Results: 1, after five weeks of modeling, the body weight of the diabetic rats decreased significantly (P0.01), and the blood sugar increased to the diabetes level in the early stage (after 24h), and the triglyceride also increased significantly in.2, and the tail flick latency of the diabetic rats was gradually prolonged, to 5W. Compared with the control group, the content of CGRP and SP in the DM group was significantly decreased in the myocardium, the dorsal root ganglion and the serum level (P0.05), and the CGRP, SP content in the DM2 group was significantly lower than that of the DM1 group (P0.05).3. Compared with the I/R group, the infarct area of the cardiac muscle in the I/R group diabetic rats increased significantly, and the ratio of cardiomyocyte apoptosis was significantly increased. In group DM, the myocardial injury indexes of group DM2 rats were significantly higher than those in group DM1. Compared with the corresponding sham operation group, the normal rats in group I/R were significantly increased in SP, CGRP in group I/R, and the increase of SP was not significantly.4. Compared with the corresponding sham operation group, the expression of ischemic myocardium in the normal rats was significant. There was no significant change in TRPV1 expression in diabetic group I/R (P0.05), and significantly lower than that in non diabetic group (P0.05), and there was no significant difference in the expression of TRPV1 in the ischemic myocardium between the DM1 group and the DM2 group. The changes of NGF content in each group were compared with the corresponding sham operation group, the normal I/R group dorsal root ganglion, the ischemic myocardium and the serum expression were significantly increased (P0.05), diabetes mellitus (P0.05), diabetes mellitus (P0.05), diabetes mellitus The expression of NGF in the I/R group was not significant. Compared with the control group, the NGF content in the DM1 group increased significantly (P 0.05), while the NGF content in the DM2 group decreased significantly (P0.05). Conclusion: 1, the diabetic rats were gradually decreasing after the injection of STZ, showing a continuous increase in the tail flick latency, but there was no significant change in the tail flick latency of the normal group; the individual diabetic rats were not significantly changed. The change rate of the tail flick incubation period was different, reflecting the different degree of peripheral and visceral sensory neuropathy, and associated with the significant reduction of the sensory nerve CGRP, SP,.2. The DM group (DM2 group) with higher tail flick latency (DM2 group) was more sensitive to myocardial ischemia reperfusion injury. It was concluded that this may be significantly lower than the DM2 group CGRP, SP content compared with the DM1 group. The changes of NGF and TRPV1 in diabetic rats may be related to the changes of sensory neuropathy and the contents of CGRP and SP in.3.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R587.2

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