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

Objective—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). Sample Population—Gastric tissues from 30 horses. Procedure—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. Results—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 ≤ 4.0. Conclusions and Clinical Re...