Effects of hydrochloric, acetic, butyric, and propionic acids on pathogenesis of ulcers in the nonglandular portion of the stomach of horses

• Published in: American journal of veterinary research Vol. 64; no. 4; pp. 404 - 412
• Main Authors: Nadeau, J.A, Andrews, F.M, Patton, C.S, Argenzio, R.A, Mathew, A.G, Saxton, A.M
• Format: Journal Article
• Language: English
• Published: United States 01.04.2003
• Subjects: acetic acid; Acetic Acid - adverse effects; Animals; butyric acid; Butyric Acid - adverse effects; Culture Techniques; electrical conductivity; Fatty Acids, Volatile - adverse effects; Female; gastric mucosa; Gastric Mucosa - drug effects; Gastric Mucosa - pathology; horse diseases; Horse Diseases - chemically induced; Horse Diseases - etiology; Horse Diseases - pathology; Horses; hydrochloric acid; Hydrochloric Acid - adverse effects; Hydrogen-Ion Concentration; ion transport; Male; Membrane Potentials - drug effects; pathogenesis; Propionates - adverse effects; propionic acid; sodium; Stomach - drug effects; Stomach - pathology; Stomach Ulcer - chemically induced; Stomach Ulcer - etiology; Stomach Ulcer - pathology; Stomach Ulcer - veterinary; stomach ulcers; Time Factors; volatile fatty acids
• ISSN: 0002-9645; 1943-5681
• DOI: 10.2460/ajvr.2003.64.404

To identify the pathogenesis of gastric ulcers by comparing injury to the nonglandular gastric mucosa of horses caused by hydrochloric acid (HCl) or volatile fatty acids (VFAs). Gastric tissues from 30 horses. Nonglandular gastric mucosa was studied by use of Ussing chambers. Short-circuit current (Isc) and potential difference were measured and electrical resistance calculated for tissues after addition of HCl and VFAs to normal Ringer's solution (NRS). Tissues were examined histologically. Mucosa exposed to HCl in NRS (pH, 1.5) had a significant decrease in Isc, compared with Isc for mucosa exposed to NRS at pH 4.0 or 7.0. Also, exposure to 60mM acetic, propionic, and butyric acids (pH, 4.0 or 1.5) caused an immediate significant decrease in Isc. Recovery of sodium transport was detected only in samples exposed to acetic acid at pH 4.0. Recovery of sodium transport was not seen in other mucosal samples exposed to VFAs at pH < or = 4.0. Acetic, butyric, and propionic acids and, to a lesser extent, HCl caused decreases in mucosal barrier function of the nonglandular portion of the equine stomach. Because of their lipid solubility at pH < or = 4.0, undissociated VFAs penetrate cells in the nonglandular gastric mucosa, which causes acidification of cellular contents, inhibition of sodium transport, and cellular swelling. Results indicate that HCl alone or in combination with VFAs at gastric pH < or = 4.0 may be important in the pathogenesis of gastric ulcers in the nonglandular portion of the stomach of horses.