Effects of biliary obstruction on gallbladder motility by the damage of interstitial cells of Cajal

Abstract

Objective To investigate the effects of acute biliary tract obstruction on gallbladder interstitial cells of Cajal ( ICCs ) and gallbladder smooth muscle contraction.Methods Three groups were designed in the study:sham operation control group (Sham),2-day bile duct ligation (BDL) group,and 2-day BDL + 2-day DBDL group.Hematoxylin-eosin staining was used to observe the gallbladder pathological changes.The network of ICCs in the gallbladder of guinea pigs was observed by methylene blue staining.The number of ICC was observed by using c-kit imnunofluorescence staining.The contraction activity of gallbladder muscle strips was recorded.Results No inflammatory changes were found in the Sham group (The inflammation score at 2nd and 4th day was 0.40 ±0.04 and 0.43 ±0.06 respectively).The inflammation scores in DBDL and BDL groups was (0.88 ± 0.0.08 ),and ( 1.68 ± 0.1 7) respectively,with the difference being significant.There was no significant difference in the netword of ICCs among Sham,BDL and DBDL groups.The number of c-kit immune positive cells in BDL and DBDL group was reduced as compared with Sham group.After DBDL,the number of c-kit immune positive cells was increased.The response values of the gallbladder strips to 1 × 10-8 mol/L CCK-8 in Sham,BDL and DBDL goups were (1.675±0.233),(1.301 ±0.229),and (1.402 ±0.234) g,and those to 10-6 mol/L Ach were (3.085 ±0.272),(2.364 ±0.238),and (2.612 ±0.278) g,respectively,which were concentrationdependent.The contraction sensitivity of gallbladder strips to CCK-8/Ach was decreased in BDL and DBDL groups as compared with Sham group (P ＜0.05). Conclusion Acute bile duct obstruction can result in the dysfunction of gallbladder contraction,which may be related to the reduced number of ICCs. Key words: Bile duct ligation; Biliary obstruction; Interstitial cells of cajal; Gallbladder smooth musclc