老龄化自发性高血压模型大鼠与SD大鼠左冠状动脉的应力松弛特性

背景：目前多数研究为正常人尸体和动物动脉血管的应力松弛特性，而老龄化自发性高血压模型大鼠与SD大鼠左冠状动脉应力松弛特性的研究鲜有报道。目的：对比分析老龄自发性高血压模型大鼠与SD大鼠左冠状动脉应力松弛特性，为高血压致血管损伤修复提供应力松弛指标。方法：对四五个月龄正常SD雄性大鼠左冠状动脉和老龄自发性高血压模型大鼠左冠状动脉各10个试样在日本岛津电子万能试验机上进行应力松弛实验，模拟人体温在(36.5±0.1) ℃的温度场下以0.05%/s的应变增加速度对试样施加应变，设定时间为7 200 s。采集100个数据，采用归一化分析的方法计算两组试样的归一化应力松弛方程。结果与结论：两组试样应力松弛曲线是以对数关系变化的，SD组试样7 200 s应变上升量大于自发性高血压模型组，差异有显著性意义(P < 0.05)。可见正常SD大鼠左冠状动脉和老龄自发性高血压模型大鼠左冠状动脉具有不同的应力松弛特性。

Left coronary artery stress relaxation properties of aging spontaneously hypertensive rats and Sprague Dawley rats

BACKGROUND:There are many studies on the stress relaxation properties of normal human corpses and animal arteries, but the research about the stress relaxation of the left coronary artery of aging spontaneously hypertensive rats and Sprague Dawley rats is rarely reported.OBJECTIVE:To comparatively analyze the left coronary artery stress relaxation properties of aging spontaneously hypertensive rats and Sprague Dawley rats in order to provide the stress relaxation index for repairing the vascular injury induced by hypertension.  METHODS:Ten left coronary artery samples of 4-5 months old normal Sprague Dawley male rats and the aging spontaneously hypertensive model rats were selected, and then put them in the Shimadzu electronic universal testing machine to do the stress relaxation test, simulated the human body temperature at (36.5±0.1) ℃, and then imposed the strain in 0.05%/s strain increases speed, the time was set as 7 200 seconds, 100 data were collected. The samples normalized creep equation of the two groups was calculated with the normalized analysis method.  RESULTS AND CONCLUSION:The samples creep curve of the two groups was changed in exponential relationship. The 7 200 seconds strain rising volume of the samples in the Sprague Dawley rats group was significantly greater than that in the spontaneously hypertensive group (P < 0.05). And there were different stress relaxation properties of the left coronary artery between normal Sprague Dawley rats and aging spontaneously hypertensive rats.