中文摘要：

为探讨不同浓度黄芩苷对热应激条件下猪近端肾小管细胞（pig kidney proximal tubular cells, LLC-PK1）细胞凋亡率及B细胞淋巴瘤/白血病-2基因（B-cellymphoma-2, Bcl-2）和Bcl-2相关X蛋白基因（Bcl-2 associated X protein, Bax）表达的影响，将培养的LLC-PK1细胞随机分为7个组，Ⅰ组为37℃空白对照组，Ⅱ组为42℃单纯热应激1 h组，Ⅲ、Ⅳ、Ⅴ、Ⅵ和Ⅶ组分别为用不同浓度黄芩苷（0.01、0.1、1、10和100μg/mL）处理组后42℃热应激1 h组，运用实时荧光定量PCR和Western blot分别检测Bcl-2和Bax基因及蛋白的表达，流式细胞仪（Annexin V-FITC/PI双染法）检测细胞凋亡率。结果表明，与Ⅰ组相比，Ⅱ组能显著诱导LLC-PK1细胞Bcl-2 mRNA的表达（P＜0.05），极显著诱导细胞Bax mRNA和蛋白的表达（P＜0.01），能极显著降低细胞Bcl-2和Bax mRNA和蛋白的比值（P＜0.01），极显著增加细胞凋亡率（P＜0.01），但对细胞Bcl-2蛋白的表达无显著影响（P＞0.05）。黄芩苷处理组与Ⅱ组相比，Ⅳ、Ⅴ和Ⅵ组LLC-PK1细胞Bcl-2 mRNA的表达量均升高，其中Ⅴ组差异极显著（P＜0.01），Ⅳ及Ⅵ组差异显著（P＜0.05），Ⅲ及Ⅶ组差异不显著（P＞0.05），而细胞Bcl-2蛋白的表达量与Ⅱ组相比均差异不显著（P＞0.05）；同样与Ⅱ组相比，黄芩苷处理的各组细胞Bax mRNA及蛋白的表达量均降低，其中Ⅴ及Ⅵ组差异极显著（P＜0.01），其余各组差异显著（P＜0.05）；除Ⅲ组外，其他各组细胞Bcl-2和Bax mRNA及蛋白的比值与Ⅱ组相比均显著升高（P＜0.05），其中Ⅴ组细胞Bcl-2和Bax蛋白的比值差异极显著（P＜0.01）；细胞凋亡率仅有Ⅲ组与Ⅱ组相比差异不显著（P＞0.05），而Ⅴ及Ⅵ组细胞凋亡率极显著低于Ⅱ组（P＜0.01），其余的Ⅳ和Ⅶ组显著低于Ⅱ组（P＜0.05）。一定浓度范围内的黄芩苷（0.1~100μg/mL）可能通过下调热应激条件下LLC-PK1细胞Bax的?

英文摘要：

The objective of this study is to explore baicalin influence B-cellymphoma-2 （Bcl-2） and Bcl-2 associated X protein （Bax） expression as well as apoptosis rates of heat-stressed pig kidney proximal tubular cells （LLC-PK1）. Readily cultured LLC-PK1 cells were randomly divided into seven groups. The cells in groupⅠwere used as blank control cultured at 37℃and cells in groupⅡwere heart-stressed at 42℃for 1 h. Cells in groupsⅢ,Ⅳ,Ⅴ,ⅥandⅦwere cultured additionally with different concentrations （0.01, 0.1, 1, 10 and 100μg/mL） of baicalin at 42℃for 1 h, respectively. Expression of Bcl-2 mRNA and Bax protein were detected with Real-time PCR and Western blot, respectively. Apoptosis rates of LLC-PK1 cells were determined with Annexin V-FITC/PI. Results showed that as compared to groupⅠ, Bcl-2 mRNA in groupⅡincreased significantly （P〈0.05）, and Bax mRNA and its protein increased extremely significantly （P〈0.01）, and both ratios between Bcl-2 and Bax mRNA and their proteins decreased significantly （P〈0.01）, and the apoptosis rates increased extremely significantly（P〈0.01）. However, there was no evident influence on Bcl-2 protein expression （P〉0.05）. Compared with groupⅡ, Bcl-2 mRNA expression significantly increased in groupⅣand Ⅵ （P〈0.05） and extremely significantly in groupⅤ（P〈0.01）, but not in groupⅢor Ⅶ （P〉0.05）, while the Bal-2 protein expression had no difference （P〉0.05）. Similarly, compared with groupⅡ, both Bax mRNA and its protein expression decreased significantly in groupsⅢ, Ⅳand Ⅶ （P〈0.05） and decreased extremely significantly in groupⅤandⅥ（P〈0.01）. Ratios between Bcl-2 and Bax mRNA and their proteins in all groups except groupⅢhad a significant increase （P〈0.05）, while the ratio between Bcl-2 and Bax protein in groupⅤincreased extremely significantly （P〈0.01）. The apoptosis rates decreased extremely significantly in groupⅤ and Ⅵ （P〈0.01）, and decreased signi