Synergistic effect of hydrochloric acid and bile acids on the pars esophageal mucosa of the porcine stomach.
OBJECTIVE
To determine effects of finely ground diet and food deprivation on pH and bile acid concentration in the proximal portion of the porcine stomach and effects of bile acids and pH on the pars esophageal mucosa in vitro.


METHODS
Sixteen 15- to 30-kg pigs.


METHODS
Gastric content samples obtained from pigs fed a finely ground pelleted or coarsely ground meal diet were assayed for gastric pH and bile acids. Stratified squamous epithelium was studied in an Ussing chamber, and histologically. Electrical conductance and transmucosal mannitol fluxes (as indices of tissue permeability) were determined at pH 4.0, 2.0, and 1.5 and in response to treatment with 0, 1, 2, or 3 mM taurodeoxycholate or glycocholate.


RESULTS
Pigs fed the finely ground feed had significantly (P = 0.01) lower proximal stomach pH than did pigs fed the coarse meal. Proximal stomach bile acids concentration was significantly (P = 0.04) higher in pigs fed the finely ground diet. The H+ and bile acids concentration increased with time after feeding. In vitro exposure of the stratified mucosa to high H+ (pH < 4.0) and bile salt concentration (> or = 1.0 mM) resulted in significant (P < 0.05) dose-dependent increase in tissue conductance and mannitol fluxes, whereas low pH or bile acids alone had little effect.


CONCLUSIONS
High H+ and bile acids concentration in the stomach of pigs fed finely ground diets or subjected to feed deprivation may contribute to ulceration of the pars esophageal tissue. Bile acids act synergistically and in dose-dependent manner, with low pH causing damage to the stratified squamous epithelium in vitro.
Lang
J
J
Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
Blikslager
A
A
Regina
D
D
Eisemann
J
J
Argenzio
R
R
D000818:Animals; D001647:Bile Acids and Salts / Q000008:administration & dosage / Q000494:pharmacology*; D004032:Diet / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004553:Electric Conductivity; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects; D004947:Esophagus / Q000166:cytology / Q000187:drug effects*; D005508:Food Deprivation; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects*; D006851:Hydrochloric Acid / Q000008:administration & dosage / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D013552:Swine / Q000502:physiology*; D013657:Taurodeoxycholic Acid / Q000494:pharmacology
D001647:Bile Acids and Salts; D013657:Taurodeoxycholic Acid; D006851:Hydrochloric Acid