| [Backgrounds and Objective] Obstructive jaundice is associated with high postoperative complications and mortality. It is controversial whether or not to relieve the jaundice before operation and which method is better, internal biliary drainage or external biliary drainage. Our previous study has found that a great amount of cytotoxic nitric oxide was produced by Kupffer cells in rats with obstructive jaundice. The elevated nitric oxide could be suppressed by internal biliary drainage, but not by external drainage, although the mechanism remains unclear yet. The aims of the present study are to explore the effects of internal and external biliary drainages on the blood levels of endotoxin (LPS) and cytokines and the expression of inducible nitric oxide synthase (iNOS) by liver tissue in rats with obstructive jaundice, in order to investigate the mechanism of internal biliary drainage being superior to external drainage.[Methods] Sixty-nine male adult Sprague-Dawley rats were randomly assigned to four groups: obstructive jaundice (OJ, n=18), internal biliary drainage (ID, n=18), external drainage (ED, n=18) and sham operation (SH, n=15). OJ was established by first operation. After seven days, both ID and ED were builded by another operation. On the 7th day after the second operation, the rats were succumbed and the specimens of blood and liver were collected. The level of serum endotoxin was detected by limulus test (LT). The concentrations of serum interlukin-2 (IL-2) and interlukin-6 (IL-6) were measured with enzyme linked immunosorbent assay (ELISA) and the iNOS expression of liver tissue was determined by SABC (Streptavidin Biotin Peroxidase complex technique) immunohistochemical method.[Results] Rat models were successfully established. After bile duct ligation, the level of plasma endotoxin was significantly elevated (42.463 pg/mL±3.486 pg/mL) compared with that in SH rats (4.136±2.002 pg/mL ) ( OJ vs ED, P=0 ) . The concentrations of serum IL-6 (212.949 pg/mL±56.546 pg/mL) and EL-2 (212.718 pg/mL±62.419 pg/mL) were also increased and the expression of liver iNOS became stronger in terms of staining area and mean optical density ( 30.539±6.255, 0.296±0.055 respectively ) . When ED was performed, rat endotoxemia was depressed (6.224±2.996 pg/ mL) (ED vs OJ, P=0) . However, the level of interlukin-2 and interlukin-6 was far from decrease and was significantly elevated (264.890±62.322 pg/mL, 269.363±76.199 pg/mL) (ED vs OJ, P=0. 017and P=0. 014 respectively). Meanwhile, the expression of liver iNOS i.e. the staining area (38.186±7.495) and mean optical density (0.399±0.086) was obviously stronger (ED vs OJ, P = 0 and P = 0. 004 respectively ). After relief of OJ by ID, the plasma endotoxin and IL-6 were decreased (4.190±1.970 pg/mL, 169.713±49.053 pg/mL) (ID vs OJ, P=0 and P=0. 014 respectively) and comparable to those in SH group (4.136±2.002 pg/mL, 145.308±38.757 pg/mL) (ID vs SH, P=0. 787 and P=0. 256 respectively ) . The concentration of serum EL-2 was decreased a little bit, but it was not statistically significant (ID vs OJ, P=0. 106 ) . The expression of liver iNOS was markedly suppressed. The staining area of iNOS was reduced (16.571±2.044) (ID vs OJ, P=0. 017 )and mean light optical decreased (0.204±0.029) (ID vs OJ, P=0) .[Conclusions] Internal biliary drainage could reverse the endotoxemia, elevated serum inflammatory cytokines and the expression of iNOS of liver tissue in rats with obstructive jaundice. However, external biliary drainage failed to do that and even deteriorated it. This study further proved that internal biliary drainage is superior to external drainage in the relief of obstructive jaundice. |
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