硒和维生素E缺乏诱导大鼠肝细胞凋亡

HEPATOCYTE APOPTOSIS INDUCED BY SELENIUM AND VITAMIN E DEFICIENCIES IN RATS

目的 研究硒 (Se)和维生素 E(VE)缺乏对大鼠肝细胞的影响。方法 以天然低Se低 VE的克山病病区粮作为饲料进行动物试验 ,与人工半合成低 Se低 VE饲料的实验互相印证 ;用光镜、电镜、流式细胞术 (FCM)、末端脱氧核苷酸转移酶介导的缺口末端标记 (TUNEL)、DNA琼脂糖凝胶电泳 5种方法进行肝细胞凋亡检测。结果 无论天然饲料还是人工半合成饲料实验 ,低 Se低 VE组光镜下均可见较多肝细胞胞浆着色深 ,核浓缩。主要分布在中央静脉周围。电镜检查天然低 Se低 VE组可见较多肝细胞核体积缩小 ,核染色质呈块状聚集在核膜下。用流式细胞术检测 ,天然低 Se低 VE组较对照组肝细胞凋亡百分率明显增加 ,补 Se和 /或 VE使调亡百分率有所下降 ,以联合补充 Se和 VE凋亡百分率下降最明显。人工半合成饲料低 Se低 VE组凋亡百分率较高 ,补 Se和 /或 VE使凋亡百分率有所下降 ,但均未达到显著差异。无论天然饲料还是人工半合成饲料实验 ,低 Se低 VE组均可见较多 TUNEL染色阳性细胞 ,加 Se和 /或 VE可使上述改变的细胞有不同程度减少。DNA琼脂糖凝胶电泳 ,无论天然还是人工半合成饲料实验低 Se低 VE组均可见 DNA梯状图象 ,其余各组未见梯状改变。结论 Se和

Objective:[WT5BZ] To verify whether dietary deficiency of selenium(Se) and vitamin E(VE) can induce hepatocyte apoptosis. [WT5FZ]Methods:[WT5BZ] The hepatocyte apoptosis was detected by using light microscope, electron microscope, FCM, TUNEL and DNA agarose gel electrophoresis in Wistar rats fed natural or semisynthetic diet deficient in Se and VE. [WT5FZ]Results:[WT5BZ] A few apoptotic hepatocytes showing cytoplasm and nucleus condensation were observed in the groups of natural or semisynthetic diet deficient in Se and VE under light microscope. Chromatin condensation and margination were seen in apoptotic hepatocytes under electron microscope in the group of natural diet deficient in Se and VE. By flow cytometry(FCM), the percentage of hepatocyte apoptosis increased significantly in the group of natural diet deficient in Se and VE (P<0.01, compared with control group), and fewer apoptotic hepatocytes were seen in the group of natural diet supplemented with Se and/or VE (P>0.05), and more significantly decreased in the group of combined supplementation of Se and VE (P<0.01). The percentage of hepatocyte apoptosis increased but not significantly (P>0.05, compared with control group) in the group of semisynthetic diet deficient in Se and VE. Many TUNEL positive hepatocytes were found in the rats fed natural as well as semisynthetic diet deficient in Se and VE and decreased after supplementation of Se and VE. The apoptotic hepatocytes occurred mainly around blood vessels. DNA “Ladder” fragmentation of apoptotic hepatocytes was shown on agarose gel electrophoresis in the group of natural or semisynthetic diet deficient in Se and VE. [WT5FZ]Conclusion: [WT5BZ]The dietary deficiencies of Se and VE can induce hepatocyte apoptosis.