Establishment of hepatic reserve function and molecular biological analysis of liver function after hepatectomy

1)比较梗阻性黄疸大鼠和对照组大鼠肝切除前后转录因子和细胞周期调控因子的差异。梗阻组肝切除后肝组织中C/eBP-α和β-β的表达和活性明显降低，Cyclin E的表达明显低于对照组。AP-1、细胞周期蛋白D1和p21的活性在两组间差异无统计学意义。这些结果表明，梗阻性黄疸抑制了肝脏C/EBP的表达和活性，导致细胞周期蛋白E的表达受损，这是肝切除术后细胞周期功能障碍的部分原因。(参考文献1)比较硫代乙酰胺诱导的肝硬变大鼠和正常大鼠肝切除后生长因子受体、转录因子和细胞周期调节因子的再生反应。肝硬变GR-…时C/EBP和AP-1活性明显受抑肝硬化组细胞周期蛋白D_1、E、A的表达均显著低于对照组。这些结果提示，C/EBP和AP-1活性受损可能通过下调细胞周期蛋白D_1、E和A的表达而导致肝硬变大鼠肝部分切除后再生能力下降。(参考文献2)3)胆汁在肝切除术后肝再生中的重要性是众所周知的。在70%肝切除前将胆汁外引流(ED组)或十二指肠引流(ID组)7d，以肝相对重量、DNA合成率和增殖细胞核抗原标记指数评价肝再生情况。术后检测细胞周期蛋白D_1、E的表达及细胞周期蛋白D_1、E相关蛋白的活性。ED组肝再生较ID组延迟。两组间细胞周期蛋白D1和E的表达及细胞周期蛋白D1相关蛋白的活性无明显差异。在肝切除术后18小时，ID组的细胞周期蛋白E相关激酶活性低于ED组。这些结果表明，肝切除术后，肠道胆汁的缺乏延迟了与细胞周期蛋白E相关的激酶失活相关的肝再生。(参考文献3)较少

1) We investigated the differences in the transcription factors and cell cycle regulators between obstructive jaundiced and control rats before and after hepatectomy. The expressions and activities of C/EBP-α and ?β were significantly decreased associated with the significantly lower cyclin E expression after hepatectomy in the jaundiced group than in the controls. The activities of AP-1, cyclin D1, and p21 were not significantly different between the two groups. These results suggest that obstructive jaundice inhibits hepatic expression and activities of C/EBP, resulting in the impaired cyclin E expression that is partly responsible for the cell cycle dysfunction after hepatectomy. (Reference 1)2) Regeneration responses in growth factor receptors, transcription factors, and cell cycle regulators after two-third hepatectomy were compared between rats with thioacetamide-induced cirrhotic and normal liver. The activities of C/EBP and AP- 1 were significantly inhibited in the cirrhotic gr … More oup compared with those in the control group, but not those of NF-kB and STAT 3. The expression of cyclin D1, E, and A was significantly decreased in the cirrhotic group compared with the control group. These results suggest that downregulation of cyclin D1, E, and A expression, which may be induced by impaired activities of C/EBP and AP-1, is responsible for the decreased regenerative capacity of cirrhotic liver after partial hepatectomy. (Reference 2)3) The importance of bile in liver regeneration after hepatectomy is known. Bile was drained externally (ED group) or into the duodenum (ID group) for 7 days before 70% hepatectomy, and liver regeneration was assessed by the relative liver weight, DNA synthesis rate, and PCNA labeling index. Posthepatectomy expressions of cyclin D1 and E, and cyclin D1- and E-associated kinase activity were also analyzed. Liver regeneration in the ED group was delayed than that in the ID group. Cyclin D1 and E expression and cyclin D1-associated kinase activity were not different between the two groups. Cyclin E-associated kinase activity was lower in the ID group than the ED group at 18 hr after hepatectomy. These results suggest the absence of intestinal bile delays liver regeneration associated with cyclin E-associated kinase inactivation after hepatectomy. (Reference 3) Less