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  • Author or Editor: Arnold R. Smith x
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Abstract

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 ≤ 7.0 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.

Full access
in American Journal of Veterinary Research

Abstract

Objective

To determine the potential effects of feeding fumonisin-containing culture material on the pulmonary clearance of blood-borne particulates and bacteria in swine.

Animals

21 healthy male pigs randomly assigned to control and treated groups.

Procedure

Control pigs were fed a standard grower ration while culture material containing fumonisins (20 mg of hydrolyzed fumonisin B1/kg of body weight/d) was added to the feed of treated pigs for 7 days. On day 8, pigs were anesthetized with halothane and catheterized, using a sterile cut-down procedure. 18 hours after recovery from anesthesia, Monastral Blue or Pseudomonas aeruginosa was infused into the right atrium of treated and control pigs for 30 minutes and pulmonary clearance was determined.

Results

Pigs that were fed fumonisin-containing culture material had a significantly (P < 0.05) decreased ability to clear Monastral Blue and P aeruginosa. Ultrastructural examination of the lung indicated that uptake of copper pigment by pulmonary intravascular macrophages was decreased in treated pigs.

Conclusions and Clinical Relevance

Fumonisins, even when fed to pigs at sub-lethal concentrations, can inhibit pulmonary intravascular macrophages from removing particulate matter and bacteria from the circulation, thus potentially predisposing swine to infectious disease. (Am J Vet Res 1996;57:1233-1238)

Free access
in American Journal of Veterinary Research