实验性心力衰竭大鼠心肌细胞细胞间黏附分子1的表达

Expression of intercellular adhesion molecule-1 in myocardial cells of experimental rats with congestive heart failure

目的:观察细胞间黏附分子1mRNA和蛋白在异丙肾上腺素诱导的充血性心力衰竭模型大鼠心肌细胞的表达,探讨细胞间黏附分子1在心力衰竭心肌重构中的作用。方法:①实验于2002-10/2003-03在黑龙江中医药大学中医基础理论实验室和哈尔滨医科大学遗传教研室分子生物学实验室完成。选用健康成年Wistar雄性大鼠36只。随机分3组,对照组、模型组、治疗组,每组12只。除对照组外,另2组皮下多点注射异丙肾上腺素,以每天20,10和5mg/kg的递减剂量连续注射3d,再以每天3mg/kg剂量维持9d,造成心力衰竭模型。于造模前1天起开始灌胃给药,治疗组给予26.5%卡托普利悬液2.25mg/kg;对照组和模型组分别予同体积8.5mL/kg双蒸水灌胃。各组连续给药6周。②6周后,进行血流动力学及病理形态学检测,同时采用反转录多聚酶链反应法和免疫组化法测定细胞间黏附分子1的mRNA和蛋白表达变化。③两组间比较采用t检验。结果:实验过程中模型组和治疗组分别死亡1和2只,进入心脏质量指数比较的对照组、模型组和治疗组大鼠只数分别为12,11,10只。①模型组大鼠室内压最大上升/下降速率、左室收缩压均明显低于对照组(t=3.546,3.961,4.368,P<0.05～0.01),左室舒张末压明显高于对照组(t=5.894,P<0.01)。治疗组室内压最大上升/下降速率和左室收缩压明显高于模型组,左室舒张末压明显低于模型组(t=2.779～2.925,P<0.05)。②模型组大鼠心脏质量指数明显高于对照组(t=4.898,P<0.01)。治疗组大鼠心脏质量指数明显低于模型组(t=2.199,P<0.05)。③模型组细胞间黏附分子1蛋白表达明显高于对照组(t=11.41,P<0.01),治疗组明显低于模型组(t=2.303,P<0.05)。④对照组心肌细胞细胞间黏附分子1mRNA未见表达,异丙肾上腺素引发心力衰竭大鼠心肌细胞细胞间黏附分子1mRNA大量表达,明显高于对照组(t=190.141,P<0.01);治疗组大鼠心肌细胞细胞间黏附分子1mRNA表达水平低于模型组,但差异不明显(P>0.05)。结论:①正常心肌细胞细胞间黏附分子1呈低水平表达,发生心力衰竭时心肌细胞细胞间黏附分子1表达增强,并与心功能恶化程度一致,它可作为监测心力衰竭进程的指标。②细胞间黏附分子1可能通过介导炎症反应参与心力衰竭心肌重构。③血管紧张素转换酶抑制剂卡托普利对心力衰竭大鼠心肌细胞升高的细胞间黏附分子1蛋白表达具有显著下调作用。

AIM： To observe the intercellular adhesion malecule-1（ICAM） mRNA and protein expressions in isoproterenol induced rat models of congestive heart failure, and explore the role of ICAM-1 in the myocardial remodeling of CHF. METHODS： This experiment was carried out in the Basic Theory Laboratory of Traditional Chinese Medicine, Heilongjiang University of Traditional Chinese Medicine and the Laboratory of Molecular Biology, Department of Heredity, Harbin Medical University from October 2002 to March 2003. Thirty healthy adult male Wistar rats were randomized into control group, model group and treatment group with 12 rats in each group. Rats in the model group and treatment group were made into CHF models by subcutaneous injection of isoproterenol at multiple points, they were injected continuously for 3 days with progressively decreased dosage of 20, 10 and 5 mg/kg, and then with a dosage of 3 mg/kg for 9 days. From 1 day before model establishment, rats in the treatment group were administrated by gastric perfusion of the suspension （2.25 mg/kg） of 26.5% captopril, and those in the control group and model group were given gastric perfusion of double distilled water （8.5 mL/kg） of the same volume for 6 weeks. ② After 6 weeks, hemodynamics and pathological morphology were assessed, and the changes of ICAM-1 mRNA and protein expressions were detected by reverse transcription-polymerase chain reaction （RT-PCR） and immunohistochemistry respectively. ③ The t test was applied in the intergroup comparison. RESULTS： In the experiment, 1 and 2 rats in the model group and treatment group died respectively, and finally 12, I l and 10 rats in the control group, model group and treatment group respectively entered the comparison of cardiac mass index. ① The maximal rates of increase/decline of left ventricular pressure and left ventricular systolic pressure in the model group were obviously lower than those in the control group （t=3.546,3.961, 4.368, P 〈 0.05-0.01）, left ventricular end diastolic pressure was obviously higher than that in the control group （t=5.894, P 〈 0.01）. The maximal rates of increase/decline of left ventricular pressure and left ventricular systolic pressure in the treatment group were obviously higher than those in the model group （t=2.779-2.925, P 〈 0.05）. ② The cardiac mass index was obviously higher than in the model group that in the control group （t =4.898,P 〈 0.01）, but markedly lower in the model group （t=2.199, P 〈 0.05）. ③ The ICAM-I protein expression was obviously higher in the model group than in the control group （t=1 1.41, P 〈 0.01）, but markedly lower in the treatment group than in the model group （t=2.303, P 〈 0.05）. ④ The ICAM-1 mRNA expression in myocardial cells was not observed in the control group, but a great amount was observed in isoproterenol induced CHF rats, which was obviously higher than that in the control group （t =190.141, P 〈 0.01）, the 1CAM-1 mRNA expression in myocardial cells was not obviously lower in the treatment group than in the model group （P 〉 0.05）. CONCLUSION： ① The ICAM-I expression is low in normal myocardial cells, but enhanced in CHF myocardial cells, and it is coincident with the deteriorated severity of cardiac function, so it can be taken as an index for monitoring the process of CHF. ② ICAM-1 may be involved in the CHF myocardial remodeling through inflammatory reaction. ③ Captopril, the angiotensin converting enzyme inhibitor, plays a role in significantly downregulating the expression of ICAM-1 protein.