中文摘要：

目的：应用非选择性β肾上腺素受体激动剂——异丙基肾上腺素（isoproterenol,ISO）连续皮下注射7d诱导心脏纤维化模型,并观察此模型中炎症调控核转录因子NF-κB的变化.方法：采用10周龄体重为280 ～320 g的SD大鼠,ISO以0.25 mg/（kg·d）剂量连续背部皮下注射7d诱导心脏纤维化模型.心脏组织切片进行苦味酸-天狼猩红染色观察纤维化,以胶原容量分数进行胶原面积定量统计.应用real-time PCR法检测心脏组织中Ⅰ型/Ⅲ型胶原及炎症因子IL-6的mRNA表达.组织切片进行HE染色观察心脏病理变化.免疫组织化学方法检测心脏组织中NF-κB在细胞内的定位,Western blot法检测心脏组织中磷酸化的NF-κB水平.结果：ISO诱导的心脏纤维化模型中天狼猩红染色面积明显大于对照（control,CON）组,且ISO组的胶原容积分数显著高于CON组（12.01±1.64vs.0.95±0.06,P＜0.001）;ISO组Ⅰ、Ⅲ型胶原的mRNA表达显著高于CON组（Ⅰ型胶原：10.51±0.47vs.0.98±0.02,P＜0.001;Ⅲ型胶原：9.58±1.33 vs.1.02±0.02,P＜0.001）.ISO组心脏组织中可见细胞核增多、聚集,提示可能炎症细胞浸润,且炎症因子IL-6的mRNA表达水平明显增加（1.64±0.18 vs.1.04±0.07,P ＜0.01）.CON组NF-κB主要定位于心肌细胞胞浆中,心肌细胞核中未见NF-κB的定位;ISO组出现明显NF-κB核转位活化,心肌细胞胞浆中的NF-κB较CON组减少,心肌细胞核及间质细胞核均可见明显的NF-κB定位,同时,ISO组心脏组织磷酸化NF-κB的水平明显高于CON组（10.83±2.05vs.1.05±0.27,P＜0.001）.结论：连续7d皮下注射ISO可成功诱导心脏纤维化模型,且此模型心脏组织中活化的核转录因子NF-κB增加.

英文摘要：

Objective：To establish a model of cardiac fibrosis induced by isoproterenol （ISO）,the non-selective β adrenoceptor agonist,injected subcutaneously for 7 days in rats,and to observe changes of transcription factor NF-κB in the model.Methods：Male SD rats weighing 280-320 g were injected with ISO [0.25 mg/（kg · d）] subcutaneously for 7 days to induce cardiac fibrosis.The collagen volume fraction was determined by quantitative morphometry of picrosirius red stained left ventricular sections.Collagen types Ⅰ/Ⅲ and IL-6 mRNA expressions were analyzed by real time PCR.The pathological changes of the heart were investigated by Hematoxylin and Eosin staining.NF-κB was localized by immunohistochemistry （IHC） and phosphorylated NF-κB levels were assessed by Western blot analysis.Results：Compared with the controls,ISO significantly elevated the sirius red stained area and collagen volume fraction （12.01 ± 1.644 vs.0.95 ± 0.067,P ＜ 0.001）.Similarly,ISO increased the mRNA expressions of collagen Ⅰ and collagen Ⅲ of the heart compared with the controls （10.51 ± 0.47 vs.0.98 ±0.02,P＜0.001 for collagen Ⅰ; 9.58 ±1.33 vs.1.02 ±0.02,P＜0.001 for collagen Ⅲ）.The number of nuclei was increased and nuclear accumulation was presented in myocardial tissue induced by ISO.The mRNA expression of IL-6 increased in ISO group （1.64 ±0.18 vs.1.04 ±0.07,P ＜0.01）.ISO induced NF-κB nuclear translocation,accompanied by an increase in phosphorylation of NF-κB （10.83 ±2.05 vs.1.05 ±0.27,P ＜0.001）.Conclusion：We conclude that the model of cardiac fibrosis can be successfully induced by ISO injected subcutaneously for 7 days in rats and the activation of nuclear factor NF-κB increased by β-adrenoceptor stimulation.