大黄对烫伤后脓毒症大鼠糖皮质激素受体表达和外周血淋巴细胞的影响

The effects of rhubarb on expression of glucocorticoids receptor and peripheral blood lymphocytes in burninginduced septic rats

目的探讨大黄对烫伤后脓毒症大鼠糖皮质激素受体（GR）和外周血淋巴细胞的影响。方法将66只健康雄性SD大鼠按随机数字表法分为假手术对照组（18只）、脓毒症模型组（24只）和大黄治疗组（24只）；每组再分为12、24和72h3个亚组。用沸水造成大鼠背部体表面积30％的深Ⅲ度烫伤，12h后腹腔注射5mg／kg的内毒素复制脓毒症模型。大黄治疗组于脓毒症制模成功后即刻用50mg／kg的大黄溶于1mL的生理盐水经胃管灌入；假手术对照组和脓毒症模型组以等量生理盐水代替大黄灌胃。检测各组大鼠外周血白细胞GR结合容量和肝细胞GR结合活性的变化；采流式细胞仪检测各组大鼠外周血CD4^＋、CD8^＋细胞及CD4^＋／CD8^＋比值。结果脓毒症模型组大鼠外周血白细胞GR结合容量和肝细胞GR结合活性均较假手术对照组明显降低，且随时间延长呈进一步下降趋势；大黄干预后随时间延长上述指标呈上升趋势，且均明显高于同期脓毒症模型组[12、24、72h白细胞GR结合容量（位点／细胞）：1515．38±300．44、1859．63±258．26、1890．50±307．88比1122．63±225．39、1008．88±150．41、724．38±91．19，肝细胞GR结合^＋活性（fmol／mg）：210．19±26．26、258．01±20．98、283．38±38．21比153．11±30．07、129．83±26．89、94．08±14．30，均P〈0．01]。脓毒症模型组12h、24h CD4^＋、CD8^＋均较假手术对照组同期有不同程度下降，24h与假手术对照组同期比较差异有统计学意义（P〈0．01和P〈0．05）；各时相间点CD4^＋／CD8^＋比值亦有明显下降，其中24h、72h与假手术对照组同期比较差异均有统计学意义（均P〈0．01）。大黄治疗组各时间点CD4^＋和CD4^＋／CD8^＋比值均有不同程度升高，其中24h、72hCD4^＋／CD8^＋比值与脓毒症模型组同期比较差异有统计学意义（1．58±0．69、1．56±0．49比1．02±0．41、1．01±1．68，均P〈0．01）。结论大黄能调节脓毒症大鼠外周血白细胞GR结合容量和肝细胞GR结合活性，通过影响外周血淋巴细胞数量，改善脓毒症免疫功能紊乱。

Objective To investigate the effects of rhubarb on the expression of glucocorticoids receptor （GR） and peripheral blood lymphocytes in burning-induced septic rats. Methods Sixty-six male healthy Sprague- Dawley （SD） rats were randomly divided into sham operated control group （n=18）, sepsis model group （n=24） and rhubarb treatment group （n=24）, each group was further randomly divided into 12, 24 and 72 hours subgroups according to different time points. The model of scald sepsis was replicated by scald injury induced by boiling water at the rat back accounting for 30% total body surface area （Ⅲ grade of scald）, and administration of eudotoxin （5 mg/kg） into the peritoneal cavity 12 hours after scald injury. After the successful establishment of septic models, the rats in the rhubarb treatment group were immediately infused with 50 mg/kg rhubarb powder dissolved in 1 mL saline through a gastric tube, while the rats in sham operated control group and sepsis model group received saline by the same way as a substitute for rhubarb. The the binding capacity of GR of peripheral blood leucocyte and binding activity of GR of hepatoeyte were analyzed by radiation ligands binding assay. The CD4^＋, CD8^＋ as well as CD4^＋/CD8^＋ ratio in peripheral blood lymphocytes were detected by flow cytometer. Results The binding capacity of GR of peripheral blood leucocyte and binding activity of GR of hepatocyte were significantly decreased in a time-dependent manner in sepsis model group compared to those of the sham operated control group, while in the rhubarb treatment group they were increased in a time-dependent manner after interference of rhubarb, and they were higher than those in the model group at the same time points [ leukocyte GR binding capacity （locus/cell） at 12, 24, 72 hours ： 1 515.38 ± 300.44, 1 859.63 ±258.26, 1 890.50 ±307.88 vs. 1 122.63 ±225.39, 1 008.88 ±150.41, 724.38 ±91.19 ; hepatocyte GR binding capacity （fmol/mg） ： 210.19±26.26, 258.01 ±20.98, 283.38±38.21 vs. 153.11±30.07, 129.83＋26.89, 94.08±14.30, all P〈0.01]. Compared with the sham operated control group, the CD4^＋ and CD8^＋ were decreased in various degrees at 12 hours and 24 hours in the septic group, at 24 hours the differences being statistically significant （P〈0.01 and P〈0.05）. CD4^＋/CD8^＋ ratios were decreased significantly at all time points, the differences were statistically significant at 24 hours and 72 hours （both P〈0.01 ） . The CD4^＋ T cell and CD4^＋/CD8^＋ ratio at all the time points were increased at various degrees in the rhubarb treatment group, and the differences from those in the sepsis model group at 24 hours and 72 hours were statistically significant （1.58±0.69, 1.56±0.49 vs. 1.02±0.41, 1.01±1.68, both P〈0.01）. Conclusion Rhubarb can modulate the binding capacity of GR of peripheral blood leucocyte and the binding activity of GR of hepatocyte, and via its influence on the number of peripheral leucocytes, the immune dysfunction in the sepsis processes is improved.