核因子-кB在70%门静脉分支高位结扎后大鼠肝脏增殖与凋亡中的意义

Effects of NF-κB on liver regeneration and apoptosis after 70% portal branch ligation in rats

目的 探讨NF кB在 70 %门静脉分支高位结扎后大鼠肝脏增殖与凋亡中的意义。方法 Wistar大鼠 6 0只 ,随机分成假手术对照组和门静脉结扎组。观察术后 0 5、1、2、3、7和 14d肝脏大体结构和血浆转氨酶的变化。运用凝胶阻滞实验 (EMSA)检测术后肝脏NF кB的活性 ,用TUNEL法对结扎侧肝细胞凋亡进行定量分析 ,光镜下观察对侧肝细胞的增殖情况 ,电镜下观察结扎侧肝脏的超微结构改变。结果 70 %门静脉分支高位结扎后 ,结扎侧肝叶呈进行性萎缩变小 ,对侧则成比例的代偿性增生。在整个观察过程中 ,全肝的总重量维持恒定 ,肝脏功能基本保持正常。NF кB的活性在术后明显升高 ,于第 2天达高峰 ,1周后基本恢复正常。TUNEL显示结扎侧肝细胞在术后凋亡明显增加 ,于第 2天达高峰 ,同时对侧肝细胞却明显增殖。电镜显示结扎侧肝脏早期出现典型的凋亡改变 ,晚期明显纤维化。结论 70 %门静脉分支高位结扎后 ,NF кB的活性明显升高 ,其可能在肝脏的增殖与凋亡中具有重要意义。

Objective To investigate the effects of NF-κB on liver regeneration and apoptosis after 70% portal branch ligation in rats. Methods Sixty Wistar rats were randomized into the control group and the portal branch ligation group. The animals were sacrificed at the 12th h, 1st, 3rd, 7th and 14th d, respectively, after the operation to determine the contents of plasma ALT. Hepatocytes were isolated and nuclear protein was extracted, DNA binding activity of NF-κB was measured by EMSA. The degree of hepatic regeneration and apoptosis were observed with microscopy and TUNEL staining. The ultrastructural changes of the liver were observed with electron microscopy. Results After 70% portal branch ligation, atrophy of the deprived lobes appeared and the perfused lobes underwent compensatory regeneration. The total liver weight and plasma ALT levels were maintained at the level of sham-operated animals throughout the experiment. After portal branch ligation, DNA binding activity of NF-κB in hepatocytes increased and reached its peak on the 2nd day. Meanwhile, the number of apoptotic hepatocytes of the deprived lobes and the number of mitotic hepatocytes of the perfused lobes reached their peaks. There were typical apoptotic changes in the early stage and evident fibrotic changes in the advanced stage of the deprived lobes. Conclusions DNA biding activity of NF-κB in hepatocytes is significantly increased after 70% portal branch ligation, which might play an important role in liver regeneration and apoptosis.