title: The role of bile composition and physical chemistry in the pathogenesis of octreotide-associated gallbladder stones.
abstract: OBJECTIVE
  Treatment of acromegaly with octreotide inhibits cholecystokinin release and gallbladder contraction and induces gallbladder stones. However, little is known about the effects of octreotide on bile composition.
  
  
  METHODS
  Fresh gallbladder bile was obtained from three groups: (1) 11 nonacromegalic patients with cholesterol gallstones, (2) 6 acromegalic patients with octreotide-associated stones (treatment, 300-600 micrograms/day for 3-66 months), and (3) 8 acromogalic patients with no stones before octreotide treatment, 5 of whom were reexamined after 3-24 months of therapy.
  
  
  RESULTS
  Compared with stone-free acromegalic patients untreated with octreotide, bile from patients with cholesterol stones and from acromegalic patients with octreotide-associated stones had greater saturation indices (mean +/- SEM) (1.52 +/- 0.17 and 1.32 +/- 0.14 vs. 0.90 +/- 0.05, respectively; P < 0.01); more cholesterol in vesicles (61.2% +/- 4.5% and 67.7% +/- 7.2% vs. 37.7% +/- 3.5%; P < 0.009); more unstable vesicles (cholesterol/phospholipid ratios, 0.97 +/- 0.12 and 0.81 +/- 0.16 vs. 0.52 +/- 0.05; P < 0.02); more rapid nucleation (< 5 and < 5 days vs. > 18 days; P < 0.003); and more deoxycholic acid (22.8% +/- 2.4% and 23.6% +/- 4.8% vs. 13.9% +/- 1.4%; P < 0.05). In the paired studies, the saturation indices increased from 0.89 +/- 0.07 before octreotide treatment to 1.12 +/- 0.03 during octreotide treatment (P < 0.02), as did the percentage of deoxycholic acid from 13.3% +/- 2.1% to 24.9% +/- 2.7% (P < 0.03).
  
  
  CONCLUSIONS
  Acromegalic patients with octreotide-associated gallstones and stone-free acromegalic patients treated with octreotide have similar changes in bile composition to those in patients with "conventional" cholesterol gallstone disease.
authors.affiliation: Gastroenterology Unit, Guy's Hospital, London, England.
authors.forename: S H
authors.initials: SH
authors.lastname: Hussaini
authors.forename: G M
authors.initials: GM
authors.lastname: Murphy
authors.forename: C
authors.initials: C
authors.lastname: Kennedy
authors.forename: G M
authors.initials: GM
authors.lastname: Besser
authors.forename: J A
authors.initials: JA
authors.lastname: Wass
authors.forename: R H
authors.initials: RH
authors.lastname: Dowling
mesh_terms: D000172:Acromegaly / Q000188:drug therapy; D000328:Adult; D000368:Aged; D001646:Bile / Q000737:chemistry* / Q000187:drug effects; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002769:Cholelithiasis / Q000139:chemically induced* / Q000737:chemistry / Q000378:metabolism; D002784:Cholesterol / Q000032:analysis; D003460:Crystallization; D003840:Deoxycholic Acid / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000009:adverse effects*; D010743:Phospholipids / Q000378:metabolism
chemical_list: D010743:Phospholipids; D003840:Deoxycholic Acid; D002784:Cholesterol; D015282:Octreotide