In vitro effects of hydrochloric acid and various concentrations of acetic, propionic, butyric, or valeric acids on bioelectric properties of equine gastric squamous mucosa

Frank M. Andrews, Benjamin R. Buchanan, Sionagh H. Smith, Sarah B. Elliott, Arnold M. Saxton

Research output: Contribution to journalArticlepeer-review


Objective-To compare the effects of hydrochloric acid (HCl) and various concentrations of volatile fatty acids (VFAs) on tissue bioelectric properties of equine stomach nonglandular (NG) mucosa.

Sample Population-Gastric tissues obtained from 48 adult horses.

Procedures-NG gastric mucosa was studied by use of Ussing chambers. Short-circuit current (Isc) and potential difference (PD) were measured and electrical resistance (R) and conductance calculated for tissues after addition of HCl and VFAs (5, 10, 20, and 40mM) in normal Ringer's solution (NRS).

Results-Mucosa exposed to HCl in NRS (pH of 1.5 and, to a lesser extent, 4.0) had a significant decrease in Isc, PD, and R, whereas tissues exposed to acetic acid at a pH of < 4.0, propionic and butyric acids at a pH of < 4.0, and valeric acid at a pH of <= 70 induced a concentration-dependent effect on reduction in these same values. Values for Isc returned to baseline (recovery of sodium transport) after addition of calcium carbonate in tissues exposed to all concentrations of VFAs except the higher concentrations of valeric acid at a pH of <= 4.0. Histologic examination revealed cell swelling in the mucosal layers below and adjacent to the stratum corneum in tissues exposed to HCl and VFAs at a pH of <= 4.0.

Conclusions and Clinical Relevance-The VFAs, especially acetic acid, in the presence of HCl at a pH of <= 4.0 appear to be important in the pathogenesis of NG mucosal ulcers in horses.

Original languageEnglish
Pages (from-to)1873-1882
Number of pages10
JournalAmerican Journal of Veterinary Research
Issue number11
Publication statusPublished - Nov 2006

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