The effect of biliary obstruction on gallbladder motility and morphology of interstitial cells of Cajal / 中华消化杂志

ABSTRACT

Objective To explore the effect of biliary obstruction caused acute acalculous cholecystitis (AAC) on ultrastructure of gallbladder interstitial cells of Cajal (ICCs),and the possible mechanism of impaired contraction of gallbladder smooth muscle. Methods Total 60 healthy adult guinea pigs were in this study. The guinea pigs AAC model was induced by common bile duct ligation (BDL). The guinea pigs were divided into five groups equally,including sham control group (Sham),BDL for 12 hours (BDL-12),24 hours (BDL-24),48 hours (BDL-48) and 72 hours (BDL-72)groups. The gallbladder specimens were collected by the end of study. Gallbladder pathological changes were observed with HE staining under light microscope. Three muscle strips were collected of each gallbladder,fixed in constant temperature water bath with different concentration of eight peptide cholecystokinin agonist (CCK-8,1010 mmol/L,10-9 mmol/L,10-8 mmol/L,10-7 mmol/L and 10-6mmol/L),acetylcholine (Ach,10-8 mmol/L,107 mmol/L,10-6 mmol/L,10-5 mmol/L,10-4 mmol/L)and potassium chloride (KC1) (60 mmol/L). The contraction activity of gallbladder muscle strips was recorded by tonotransducer. The ultrastracture changes of gallbladder ICC in sham,BDL-12 and BDL-72 groups was examined by transmission electron microscopy. Results There was no obvious inflammation in Sham and BDL-12 groups. Compared with sham group,there were significant differences of biology score of gallbladder in BDL-48 and BDL-72 groups (P＜0. 05). After adding CCK-8,Ach and KC1,the contraction amplitude of gallbladder muscle increased in each group,and in dose-dependent manner. Compared with sham group,the effect value of each other groups decreased significantly (P＜0. 05). Compared with sham group,the morphology of ICC changed in BDL-12group,and more obvious in BDL-72 group. Conclusion Biliary obstruction can induce AAC. At the earlier stage of ACC,the impaired contraction of gallbladder smooth muscle present even without gallbladder inflammation occurrence. ICC may play an important role in impaired contraction.