Effect of experimental acalculous cholecystitis on gallbladder smooth muscle contractility

Abstract

Gallbladder motility is impaired in chroniccholelithiasis but has not been studied in acuteacalculous cholecystitis. The aim of this study was todetermine the effects of acute acalculous inflammation on gallbladder contractility using the commonbile duct ligation (CBDL) model in guinea pigs. Threegroups of guinea pigs were studied: CBDL, normal, andsham surgical controls. Gallbladder dimensions were measured, and muscle strips were used forhistology and in vitro contractility studies. CBDLresulted in progressive gallbladder distension,increased serum bilirubin, and gallbladder inflammation.There was a progressive decline in musclecontractility in the CBDL group as evidenced by adecrease in the contractile response to potassium andbethanechol with the duration of CBDL. In conclusion,CBDL in the guinea pig produces acute gallbladderinflammation and decreased gallbladder musclecontractility. Direct inhibition of muscle function isindicated by impaired contractile responses to potassiumdepolarization and bethanechol stimulation. Although themechanism of the decrease in contractility with CBDL isunknown, we speculate that impaired muscle contractilityis secondary to inflammation and may play a role in the clinicopathology of acute acalculouscholecystitis.