乌司他丁对脂多糖致急性肺损伤大鼠肺组织糖皮质激素受体α和β表达的影响

Influence of ulinastatin on expressions of glucocorticoid receptors alpha and beta in lung tissue of rats with LPS- induced acute lung injury

目的探讨乌司他丁对急性肺损伤(acute lung injury,ALI)大鼠肺组织糖皮质激素受体α(glucocorticoid receptor alpha,GRα)、糖皮质激素受体β(glucocorticoid receptor beta,GRβ)表达的影响。方法将72只成年雄性SD大鼠随机分为3组:空白对照组(n=24)、脂多糖组(LPS组,n=24)和脂多糖加乌司他丁组(LU组,n=24),各组又分为4、8、12、24 h 4个不同时间点,每个时间点各6只。LPS组腹腔注射LPS(5 mg/kg);LU组腹腔注射LPS(5 mg/kg)后,即刻腹腔注射乌司他丁(10万U/kg)。各组补足生理盐水至腹腔注射总体积为1 ml。光镜下观察肺组织HE染色病理学变化;同时测定大鼠肺湿干重比(W/D);采用蛋白印迹分析技术检测GRα、GRβ的表达。以灰度值表示其相对表达水平。结果病理检查证实大鼠ALI造模成功。在各时间点3组大鼠肺组织GRα、GRβ的表达:LPS组大鼠肺组织GRα表达水平均低于对照组(P均<0.01),GRβ均高于对照组(P均<0.01);LU组GRα表达水平均高于LPS组(P均<0.05),但仍低于对照组(P均<0.05),GRβ与GRα相反。LPS组内各时间点肺组织GRα、GRβ表达水平比较差异有统计学意义(P<0.05,P<0.01),GRα于8 h降到最低,然后递升;GRβ于8 h达到最高,然后递降。LU组内各时间点肺组织GRα、GRβ表达水平比较差异有统计学意义(P<0.05,P<0.01),随时间延长GRα表达递降,GRβ递增并于8 h达到最高,然后递降。结论 ALI大鼠GRα和GRβ在肺组织中的表达较正常肺组织有所改变,乌司他丁对ALI大鼠有保护作用,可能与其可调控GRα和GRβ的表达有关。

Objective To investigate the effects of ulinastatin on the expressions of glucocorticoid receptors alpha（ GRα）, glucoeortieoid receptor beta（GRβ） in lung tissue of rats with lipopolysaecharide （LPS）-induced acute lung injury （ALl）. Methods Seventy-two adult male Sprague-Dawley rats were randomly divided into blank control group （ n = 24 ） , LPS group （ n = 24 ） and LPS plus ulinastation group （ LU group, n = 24 ）. The rats ALl models were established by intraperitone- al injecting LPS （5 mg/kg ）in LPS group and LU group, and ulinastatin （100 000 U/kg）was immediately given after mod- eling by intraperitoneal injecting in the other side of the abdominal cavity in LU group. All groups were respectively re-di- vided into four subgroups of different time points according to experimental times ：4 h, 8 h, 12 h and 24 h （ n = 6 each ）. The normal saline was supplied in all rats so as to make the total volume of intraperitoneal injected fluid equal. The pathological changes of lung tissues were observed under light microscope after HE staining. The ratio of wet to dry weight （ W/D ） of lung tissue was determined. The expressions of GRα and GRβ were detected by Western blot method. The relative expres- sion level was indicated by gray value. Results The result of pathology examination showed that ALI rat models were suc- cessfully established. In LPS group,the expression levels of GRα at each time point were significantly lower than those in control group （all P 〈 0.01 ） ,and the expression levels of GRβ at each time point were significantly higher than those in control group （ all P 〈 0.01 ）. In LU group, the expression levels of GRα at each time point were significantly higher than those in LPS group （P 〈0.05 or P 〈0.01 ）but still lower than those in control group （ all P 〈0.05） ,while the expression levels of GRβ were just the opposite results from GRα expression levels. In LPS group, there were significantly differences in expression levels of GRα and GRβ at different time points （ P 〈 0.05 or P 〈 0.01 ） ; GRct level was the lowest at 8 h and then gradually increased;GRβ level was the highest at 8 h then gradually decreased. In LU group, there were significantly differences in expression levels of GRα and GRβ at different time points （ P 〈 0.05 or P 〈 0.01 ） ; GRa levels decreased gradually with the prolongation of time, while GRβ level was the highest at 8 h then decreased gradually. Conclusions The expressions of GRα and GRβ in lung tissues of ALI rats have some different changes with normal lung tissues. Ulinastatin has a protective effect on lung tissues of ALI rats, and it might be associated with regulating the expressions of GRα and GRβ.