Abstract: Objective：To investigate the effects of internal and external biliary drainage on liver regeneration of the obstructive jaundice rats after partial hepatectomy.
Methods：The rat models of obstructive jaundice with 70% liver resection were successfully constructed. All the 120 rats were randomly divided into the control group: rats received middle and left hepatic lobectomy; internal drainage group: a drainage tube was placed between the dilated bile duct and the duodenum; external drainage group: a drainage tube was placed in the dilated bile duct. There were 40 rats in each group. Rats in the internal and external drainage groups received middle and left hepatic lobectomy at postoperative day 7. The blood and hepatic tissues were collected at postoperative day 0, 1, 2, 4, 12, 24, 48, 72 hours after operation, and the rate of liver regeneration and mitotic index were determined. The expression of proliferating cell nuclear antigen (PCNA) and signal transducer and activator of transcription 3 (STAT3) in the hepatic tissues were detected by immunohistochemistry, and the levels of tumor necrosis factor α (TNF α) and interleukin6 (IL6) were detected by ELISA, and the mRNA expressions of TNF α and IL6 were detected by RT PCR. All data were analyzed using the one way analysis of variance or SNK test.
Results：Within 72 hours after partial hepatectomy, the rate of liver regeneration of the internal drainage group was 94.86%±12.72%, which was significant higher than 62.39%±8.01% of the external drainage group and 45.77%±5.41% of the control group ( F=33.62, P <0.05). The mitotoic index and PCNA levels of the 3 groups had obvious increase at postoperative hour 12, and the mitotoic index and PCNA levels of the external drainage group reached peak at postoperative hour 24, which were 24.47%±4.01% and 88.1%±9.2%, respectively. the mitotoic index and PCNA levels of the control group and the external drainage group reached peak at postoperative hour 48, which were 15.80%±1.08%, 58.3%±5.8% and 18.40%± 1.12%, 70.2%±6.9%, respectively. The mitotoic index and PCNA levels of the internal drainage group were significantly higher than those of the control group and the external drainage group ( P <0.05). The expression of STAT3 expression of the internal drainage group reached peak at postoperative hour 4, which was 42.6%±3.6%; the expression of STAT3 expression of the control group and the external drainage group reached peak at postoperative hour 12, which were 22.9%±2.0% and 29.2%±3.7%. The peak level of STAT3 of the internal drainage group was significantly higher than those of the control group and the external drainage group ( P<0.05). The levels of TNF α and IL 6 of the internal drainage group reached peak at postoperative hour 12, which were (227±23)U/L and (256±32)U/L; the levels of TNF α and IL 6 of the control group and the external drainage group reached peak at postoperative hour 24, which were (309±41)U/L and (388±40)U/L, (287±30)U/L and (346±33)U/L, respectively. The levels of TNF α and IL 6 of the internal drainage group at postoperative hour 0, 1, 2, 4, 12, 24, 48, 72 were significantly lower than those of the control group and the external drainage group ( P <0.05). The expressions of TNF α mRNA of the control group, internal drainage group and external drainage group reached peak at postoperative hour 4, which were 0.92±0.14, 0.39±0.05, 0.80±0.15, respectively. The expressions of IL6 mRNA reached peak at postoperative hour 12, which were 0.79±0.07, 0.38±0.06, 0.63±0.10, respectively. The expressions of TNF α mRNA and IL 6 mRNA of the internal drainage group at postoperative hour 0, 1, 2, 4, 12, 24, 48, 72 were significantly lower than those of the control group and the external drainage group ( P<0.05).
Conclusions：Both internal and external drainage can improve liver regeneration of obstructive jaundice rats following partial hepatectomy, while the effect of internal drainage is superior. Internal biliary drainage has influence on the expression of STAT3 by decreasing the levels of TNF α and IL 6, and help to improve liver regeneration of obstructive jaundice rats following partial hepatectomy.