【摘要】 目的探讨银杏叶制剂对在哮喘免疫学发病机制中起关键作用的T淋巴细胞部分生物学功能的影响。方法14只SD大鼠随机分成哮喘和正常两组,每组7只。从每只大鼠外周血分离出T淋巴细胞进行分组培养,72h后用RT-PCR检测各组IL-2、IL-4、IL-5mRNA的表达量,Westernblot检测各组细胞膜与细胞浆蛋白激酶Cα(protein kinase Cα,PKCα)的表达比率。结果IL-2、IL-4、IL-5mRNA表达量在哮喘组分别为0.58±0.086、1.03±0.12、0.48±0.08,正常组分别为0.45±0.03、0.35±0.08、0.15±0.05,各因子两组间比较差异有统计学意义(P<0.01);哮喘组T淋巴细胞给予BN-52021干预后IL-2、IL-4、IL-5mRNA的表达量明显下降(分别为0.49±0.05、0.55±0.09、0.27±0.05,P<0.05);正常组IL-2/IL-4mRNA的比值为1.27±0.20,哮喘组为0.60±0.18,两组比较差异有统计学意义(P<0.01),其中哮喘组给予BN-52021干预后比值有所增大0.92±0.15,与未干预组比较有明显变化(P<0.01)。哮喘PMA+BN-52021干预组IL-2、IL-4、IL-5mRNA表达量分别为1.52±0.25、1.99±0.36、0.68±0.21,明显低于哮喘PMA干预组(P<0.05),而PMA+Ro31-8220组与PMA+Ro31-8220+BN-52021干预组比较差异无统计学意义(P>0.05)。哮喘空白组PKCα在T淋巴细胞胞膜与胞浆的表达量比率为0.629±0.093,显著高于正常对照组(0.056±0.012,P<0.01),BN-52021干预后哮喘组比率较未干预组明显下降0.395±0.098(P<0.05),PMA+BN-52021干预组PKCα比率为0.719±0.163,较PMA干预组(1.28±0.28)低(P<0.05);哮喘各组T淋巴细胞胞膜与胞浆PKCα表达量的比率与IL-4mRNA表达量的相关性分析(n=42,r=0.845,P<0.01)显示呈明显正相关。结论银杏叶制剂对体外培养的哮喘大鼠T淋巴细胞因子IL-2、IL-4、IL-5的分泌均具有抑制作用,而对IL-2分泌的抑制作用相对较弱;银杏叶制剂对哮喘大鼠T淋巴细胞胞膜与胞浆PKCα的表达量比率具有明显的下调作用。更多还原

【Abstract】 Objective To investigate therapeutic effect of Ginkgo biloba extract on bronchial asthma. Methods Fourteen SD rats were randomly divided into two groups, 7 rats were sensitized as asthmatic model and the others as healthy controls. Results The quantity of IL-2, IL-4 and IL-5 mRNA in blank group of asthmatic models(0.58±0.086, 1.03±0.12 and 0.48±0.08 respectively), significantly increased (P<0.05). The quantity of IL-2, IL-4 and IL-5 mRNA decreased significantly when the T lymphocytes of asthmatic model rats were cultured with BN-52021(0.49±0.05, 0.55±0.09 and 0.27±0.05 respectively), P<0.05. The ratio of IL-2/IL-4 mRNA in normal rats was 1.27±0.20, which was significantly higher than that in asthmatic model rats( 0.60 ±0.18, P<0.01). BN-52021 significantly increased the ratio when the T lymphocytes of asthmatic model rats CM(43were cultured with it(P<0.01). BN-52021 significantly counteracted the level of IL-2, IL-4 and IL-5 mRNACM) that increased by PMA(P<0.05), but the decreasing effect was less than the Ro31-8220, a specific inhibitor of PKCα(P<0.05). BN-52021 failed to further counteract the level of IL-2, IL-4 and IL-5 mRNA increased by PMA which had significantly decreased by the Ro31-8220. The expression ratio of PKCα in membrane and cytoplasm of T lymphocytes of asthmatic model rats was significantly higher than that in normal rats(P<0.01), and BN-52021 significantly decreased the ratio when the T lymphocytes were cultured with it(P<0.05). Furthermore, it also significantly counteracted the expression ratio of PKCα in membrane and cytoplasm which increased by PMA(P<0.05). The expression ratio of PKCα in membrane and cytoplasm was positively correlated with the level of IL-4 mRNA in T lymphocytes cultured in vitro in asthmatic model rats group(n=42, r=0.845, P<0.01). Conclusion Ginkgo biloba extract depress the expression of IL-2, IL-4 and IL-5 mRNA of asthmatic model rat T lymphocytes in vitro. However, the inhibition effects were distinct in degree, so the balance of IL-2/IL-4 was changed. Ginkgo biloba extract inhibits the expression ratio of PKCα in membrane and cytoplasm. It is possible that Ginkgo biloba extract influences the production of interleukin and the balance of T_H1/T_H2 in the asthmatic model rats through its influence on the PKC signal pathway.更多还原