title: Cholesterol crystals enhance and phospholipids protect against pancreatitis induced by hydrophobic bile salts: a rat model study.
abstract: OBJECTIVE
  The role of bile composition in the pathogenesis of biliary pancreatitis is unknown. The objective of this experiment was to explore the potential role of bile salts, phospholipids, and cholesterol crystals in the pathogenesis of biliary pancreatitis in a rat model.
  
  
  METHODS
  Model systems composed of taurodeoxycholate (TDC), mixed bile salts (MBS), or tauroursodeoxycholate (TUDC) [in 10 mM phosphate-buffered saline (PBS), pH 7.4], with or without cholesterol crystals or phosphatidylcholine, were infused into bile ducts of male Sprague-Dawley rats. Twenty-four hours later, animals were killed for histopathologic scoring of (peri)pancreatic inflammation.
  
  
  RESULTS
  : Severity of acute pancreatitis depended on bile salt hydrophobicity (TDC > MBS >> TUDC = PBS; histopathologic scores: 25.6 +/- 0.5, 23.0 +/- 1.5, 14.4 +/- 2.2, 14.8 +/- 1.0, respectively; P < 0.001), with corresponding differences in serum lipase concentration. Phosphatidylcholine protected against detrimental effects of TDC at physiological, but not at low, concentrations (scores: 19.5 +/- 2.3 vs 28.3 +/- 1.9 in case of Phosphatidycholine/(TDC + Phosphatidycholine) ratios 0.25 or 0.05, respectively). Cholesterol crystals increased severity of pancreatitis in model systems containing TDC or MBS, but not TUDC or PBS (33.2 +/- 0.4, 29.6 +/- 1.2, 18.6 +/- 1.5, 18.5 +/- 2.2, respectively; P < 0.001).
  
  
  CONCLUSIONS
  In the rat model, hydrophobic bile salts and cholesterol crystals aggravate biliary pancreatitis, whereas phospholipids have a protective effect.
authors: Gastrointestinal Research Unit, Departments of Gastroenterology and Surgery, University Medical Center Utrecht, The Netherlands. K.J.vanerpecum@azu.nl
authors: L Paul
authors: LP
authors: van Minnen
authors: Niels G
authors: NG
authors: Venneman
authors: Jaap E
authors: JE
authors: van Dijk
authors: André
authors: A
authors: Verheem
authors: Hein G
authors: HG
authors: Gooszen
authors: Louis M A
authors: LM
authors: Akkermans
authors: Karel J
authors: KJ
authors: van Erpecum