In vitro effects of hydrochloric and lactic acids on bioelectric properties of equine gastric squamous mucosa.

This research focused on understanding the effects of lactic acid on the electrical properties, sodium transport, and tissue resistance of horse gastric tissue in hopes of understanding its role in causing gastric ulicides. Results showed a decrease in tissue resistance and electrical activity when exposed to hydrochloric or lactic acid, but the values returned to normal after return to neutral pH.

Research Objectives and Methods

• This research was designed to understand the impacts of Lactic acid on the bioelectric properties, sodium transport and tissue resistance of equine nonglandular (NG) mucosa, which is a part of the horse stomach lining.
• The researchers used gastric tissues taken from 13 mature horses as subjects for their study.
• These tissues were studied in Ussing chambers, a device used to measure the short-circuit current in epithelial tissues, to measure their electrical and biochemical properties.
• The tissues were subjected to hydrochloric acid (HCl) and lactic acid (LA) at varying concentrations and the effects were measured and analyzed.

Results of the Study

• A significant decrease in short-circuit current (Isc) and potential difference (PD) was observed in tissues exposed to HCl or LA in a normal Ringer’s solution with a pH of 1.5 and, to a lesser extent, pH 4.0.
• However, when the tissues were exposed to a high concentration of LA in a normal Ringer’s solution, there was an increase in conductance (G), the ability of a conductor to transmit electricity, but this increase was not statistically significant.
• Interestingly, once the solution’s pH was returned to neutral (pH 7.0), the values returned to baseline, suggesting that the changes caused by the acids were possibly reversible.
• Histological changes in the tissue were consistent with damage caused by HCl.

Conclusions of the Study

• The researchers concluded that exposure to HCl caused significant changes in the bioelectric properties of horse gastric tissue.
• However, the addition of LA did not have a remarkable effect on the tissues, apart from the changes that were seen with HCl alone.
• These findings suggest that HCl, and not lactic acid, mainly causes changes to the digestive tissue of horses, potentially creating a greater risk for gastric ulcers.