胰岛素对烟雾吸入性损伤大鼠肺组织细胞凋亡及Bcl-2和Bax蛋白表达的影响

目的 探讨胰岛素对烟雾吸入性损伤大鼠肺组织细胞凋亡及Bcl-2和Bax蛋白表达的影响.方法 将成年清洁级雌性SD大鼠66只随机分为3组,正常对照组6只、吸入性损伤组和胰岛素治疗组各30只.胰岛素治疗组于烟雾吸入性损伤后皮下注射胰岛素5 U/kg,吸入性损伤组同样致伤后于相同部位注射等体积的生理盐水,正常对照组不做任何处理.各组均在伤在2 h、6 h、12 h、24 h、48 h监测血糖值.光镜进行肺组织切片病理形态学观察.采用原位末端标记法TUNEL观察肺组织细胞凋亡,免疫组织化学染色法检测抗凋亡蛋白Bcl-2及Bax的表达变化.结果 光镜观察HE切片,正常对照组大鼠肺泡结构清晰完整.吸入性损伤组大鼠肺组织肺泡间隔增宽、炎细胞浸润,胰岛素治疗组与吸入性损伤组比较病理表现有所减轻.凋亡指数（AI）、Bax 和 Bcl-2在各时间点均明显高于正常对照组（P〈0.01）.胰岛素治疗组伤后2 h AI、Bax和Bcl-2和吸入性损伤组间差异无统计学差异（P〉0.05）,但12 h以后两组AI、Bax和Bcl-2比较时差异均有高度统计学意义（P〈0.01）,24 h各值达高峰,差异也具有高度统计学意义（P〈0.01）.结论 吸入性损伤后早期给予胰岛素可以直接促进Bcl-2蛋白表达,抑制Bax等促凋亡蛋白的表达,对吸入性损伤后肺脏组织细胞的凋亡有抑制作用,在肺损伤早期起到保护肺组织作用.

Effect of insulin therapy on apoptosis and the expressions of Bcl-2,Bax in smoke inhalation injury in rats model

Objective To investigate the influence of insulin therapy on cell apoptosis and the expressions of Bcl-2 and Bax in smoke inhalation injury in rats. Methods Sixty-six clean level adult female SD rats were randomly divided into three groupsnormal control group （n = 6） , inhaled damage group （n = 30） and insulin therapy group （n = 30）. Normal control group was not injured, insulin therapy group was subcutaneously injected 5 U/kg insulin after smoke inhalation injury, and inhaled damage group was injected the same volume normal saline. Blood glucoses in all the groups were detected at 2 h, 6 h, 12 h, 24 h and 48 h after injured. The pathological morphology changes in lungs were also examined under the optical microscope. The transferase mediated nick end labeling TUNEL method was employed to measure lung tissue cell apoptosis. Immunohistochemical method was used to detect anti-apoptotic protein Bcl-2 and Bax expression change. Results HE slices were under the optical microscope. Normal rats＇ alveolar structure was clear. Lung tissues of the inhaled damage group were alveolar interval widened, infiltrated with inflammatory cells. Compared with inhaled damage group, insulin therapy group got pathological features mitigated. Apoptosis index （ AI）, Bax and Bcl-2 in all the groups were significantly higher than normal control group （P 〈 0.01 ）. The difference of AI, Bax and Bcl-2 in insulin therapy group and inhaled damage group （ P 〉 0.05 ） was not statistically significant at 2 h, but after 12 h there was the statistically significant difference between the insulin therapy group and the inhaled damage group （P 〈0.01）, all reached to the peak value at 24 h, and all had the statistically significant differences （P 〈 0.01 ）. Conclusion Insulin can increase the expression of Bcl-2 and decrease the AI and the expression of Bax, and inhibit the cell apoptosis, protect the injured lung tissue in rats.