Role of abnormal nerve conduction in the pathogenesis of congenital choledochal cyst

Abstract

Objective To observe the expression levels of interstitial cells of Cajal (ICCs) and neurotransmitters in the extrahepatic biliary of congenital choledochal cysts (CCC),and to explore the role of abnormal nerve conduction in the pathogenesis of CCC.Methods A total of 38 child patients with CCC,15 males and 23 females,were randomly enrolled in this study and underwent cyst excision and biliary revascularization.The specimens were obtained from the distal cyst wall,the proximal cyst wall and gallbladder wall respectively and were classified into the corresponding groups.The expression of ICC was detected by immunotluorescence analysis and that of choline acetyltransferas (CHAT) and neuronal nitric oxide synthase (nNOS),the key enzymes for synthesis of acetylcholine and nitric oxide respectively,was analyzed by real-time polymerase chain reaction (RT-PCR).All of data were analyzed by SPSS 13.0 software for Windows.Results There was significant difference in the expression of ICCs between the distal cyst wall and the proximal cyst wall,also between the distal cyst wall and gallbladder wall (P ＜ 0.01).However,there was no significant difference between the the proximal cyst and gallbladder (P ＞ 0.05).The expression level of CHAT in the proximal cyst wall (1.39 ±0.11) and gallbladder wall (1.32 ±0.14) was significantly lower than in the distal cyst wall (1.78 ±0.21,P ＜0.05),but no significant difference existed between the proximal cyst wall and gallbladder wall (P ＞ 0.05).The expression level of nNOS in the proximal cyst wall (1.64 ±0.16) and gallbladder wall (1.60 ±0.13) was higher than in the distal cyst wall (1.14±0.11,P ＜ 0.05),but no significant difference existed between the proximal cyst and gallbladder (P ＞ 0.05).There was no significant difference in the expression levels of CHAT and nNOS in the the distal cyst wall between type Ⅰ CCC (1.95 ±0.27,and 1.14 ±0.12) and type ⅣW CCC (1.81 ±0.08 and 1.11 ± 0.13,P ＞0.05).However,there was significant difference in the expression of them in the proximal cyst wall between type Ⅰ CCC (1.04 ±0.17 and 1.95 ±0.24) and type Ⅳ CCC (1.39 ±0.13 and 1.70 ± 0.20,P ＜ 0.05).Conclusion The differential expression of ICC,and excitatory and inhibitory neurotransmitter in the different parts of extrahepatic biliary of CCC are probably reasons of CCC formation.The abnormal expression and distribution of the two neurotransmitters probably result in the different types of CCC. Key words: Choledochal cyst, congenital; Enteric nerve ; Interstitial cell of Cajal; Neurotransmitter; Choline acetyltransferas; Neuronal nitric oxide synthase