Effects of bile, infection and pressure on pancreatic duct integrity

Abstract

Ionic flux, potential difference and mucosal ultrastructure have been studied in the rat bile-pancreatic duct and the effects of pressure, bile and infection on the duct evaluated. The duct remained stable after perfusion with control solution under low pressure and high pressure produced widening of intercellular spaces only. Perfusion with a bacterial solution of Escherichia coli did not effect significant changes. Sterile human bile disturbed the integrity of the duct by increasing ionic flux, altering potential difference and producing reversible ultrastructural changes of cell oedema. High pressure increased these changes. Infected human bile under high or low pressure was by far the most toxic substance tested. Perfusion with infected bile led to irreversible duct damage and complete loss of duct integrity. Pressure and infected bile may have a role in damaging duct integrity and could thus play an integral part in the genesis of acute gallstone pancreatitis.

Bile Infection and Bile Acids Concentration in Bile in Acute Biliary Pancreatitis

“…Experimental studies on animals showed that presence of bacteria in bile caused the development of AP, unlike the aseptic bile (11,20,24,51). Other studies emphasized the role of increased pressure in pancreatic ducts, which next to bile infection would have a signifi cant share in evoking infl ammatory process within the pancreatic gland (11,20). Obtained own results in group of patients with SAP (73% of infected bile in CBD and 80% in gall-bladder) are higher than those in control group (respectively 62% and 52%), although this difference is of no statistical signifi cance.…”

“…In case of coexisting cholelithiasis, bacteria colonizing gall-bladder and bile ducts are the fi rst element. Bile acids are the second potential factor, as their damaging infl uence on epithelium of bile ducts and pancreatic ducts, as well as pancreatic follicular cells was confi rmed by experimental works (11)(12)(13)(14)(15)(16).…”

“…Experiments on animals proved that infected bile may be the factor initiating acute pancreatitis, especially with congestion by deposit in papilla of Vater, with co-existing pressure increase within the lumen of pancreatic ducts (11,20,21), and it is the possible source of expanding infection within the area of infl ammatory-changed pancreas (22)(23)(24)(25)(26). Lack of data concerning bile infection in patients with cholelithiasis and co-existing acute pancreatitis.…”

The effects of bile acids on pancreatic ductal cells

“…Therefore, researchers extensively investigated the effect of BAs on the morphology and permeability of the main pancreatic duct. In these in vivo studies various BAs were perfused through the cannulated main duct and the permeability of the pancreatic duct mucosal barrier was measured using different techniques (5,15,(37)(38)(39). It has been shown that BAs in high concentrations (2-15 mM), made the ducts permeable to molecules as large as 20,000-daltons, whereas they are normally impermeable to molecules over 3,000-daltons (5,15).…”

“…It was also highlighted that infected bile is more harmful to the duct cells than sterile bile (5,37,38). The higher toxicity of infected bile is probably due to bacterial deconjugation, which produces more toxic unconjugated BAs.…”