Objective To investigate the effects and significance of nerve growth factor (NGF) and its high affinity receptor of tyrosine kinase A (TrkA) expressions on proliferative connective tissue of bile duct in rats after bile duct ligation (BDL). Methods Forty-six female Sprague-Dawley rats were randomly divided into two groups: control group ( n =6) and BDL group ( n =40). The model of obstructive jaundice in rat was made by bile duct ligation, then duodenohepatic ligament was taken and treated with anti-NGF and anti-TrkA receptor antibody. Expressions of NGF and TrkA receptor in connective tissue of bile duct were investigated by immunohistochemistry, blood specimens were collected from left ventricle to detect serum total bilirubin (TB) and alanine aminotransferase (ALT). Results After BDL, TB level obviously elevated in the third day, and continued until the fourteenth day, then descended. By day 21 and 28, it returned to normal level. Compared with normal bile duct, due to bile stasis, an increased thickness of the bile duct wall was observed by microscope which correlated with the proliferation and differentiation of connective tissue cell. NGF and TrkA were expressed by the cell membrane and the cytoplasm of connective tissue cell and inflammatory infiltration cell after BDL. The trend between their expressions and bilirubin levels was similar. Conclusion NGF and its receptor TrkA regulate the proliferate and differentiation of connective cell in bile duct. They may play a key role in the formation of bile duct scar, which seems to be hardly reversed by relief of bile stasis in a short time.
To investigate the mechanisms of hepatic injury after biliary obstruction. After a rat model of complete biliary obstruction(CBO) was induced, hepatocyte mitochondria was isolated and the calcium content of mitochondria, the contents of liver malondialdyhyde (MDA) and superoxide dismutase (SOD), the levels of serum T-Bil, ALT, ALP and GGT were measured in each group. Results: After CBO, mitochondrial calcium content, liver MDA and serum T-Bil, ALT, ALP, GGT became increased progressively, compared with control group (Ｐ＜0.05); the liver SOD was decreased markedly (Ｐ＜0.05). Mitochondrial calcium content was highly positively correlated with liver MDA content, serum ALT and ALP, r values were 0.967, 0.924 and 0.919 respectively (Ｐ＜0.01). The liver MDA content was highly positively correlated with serum ALT and ALP, r values were 0.949 and 0.843 respectively (Ｐ＜0.01). Conclusions: Mitochondrial calcium overload and liver lipid peroxidation may be the important mechanisms of hepatic injury induced by biliary obstruction.
In order to study rheologic property of bile flow between gallbladder and biliary duct during biliary obstruction,we made a model of complete biliary obstruction(CBO)in dogs.The results showed that:①The behavior of bile flow between gallbladder and biliary duct in noemal dogs belonged to Casson flow;②When the duration of CBO prolonged,the behavior of bile flow between gallbladder and biliary tract in the CBO dogs still belonged to Casson flow.The changes of yield stress and apparent viscosity at high or low shear rate in bile flow of the biliary duct were similar to that in bile flow of the gallbladder.