Effect of hydrochloric acid, pepsin, or taurocholate on bioelectric properties of gastric squamous mucosa in horses.

This research investigates how various substances, such as hydrochloric acid, pepsin, and taurocholic acid, influence the bioelectric properties of gastric squamous mucosa (the protective lining of a horse’s stomach). The study suggests extended exposure to stomach acid, with or without pepsin or taurocholic acid, could lead to reduced resistance of the gastric lining, possibly leading to stomach ulcers or erosions in horses.

Purpose and Methodology of the Study

• This study aimed to investigate the effect of pH levels (with or without pepsin or taurocholic acid) on the bioelectric properties of the gastric squamous mucosa in horses. This tissue is a significant line of defense against pathogens and harmful compounds in the stomach.
• For the study, gastric tissues devoid of gastric disease were collected from 16 adult horses. The researchers opted for healthy horses to avoid any interference from pre-existing conditions.
• The bioelectric properties of the squamous mucosa were then measured using modified Ussing chambers. Ussing chambers are devices used to measure the electric potential difference across a membrane tissue.
• Following this, the tissues were exposed to mucosal pepsin (a protein-digesting enzyme) or taurocholic acid (a bile acid) under neutral (pH 7.4) or acidic conditions (pH 1.7).

Study Findings

• The results obtained from the study concluded that the exposure of mucosal sheets to an acidic pH instigated an immediate and sustained decrease in transmembrane potential difference and calculated tissue resistance. In other words, the tissue’s ability to resist changes in electrical potential decreased with increased acidity. This suggests a vulnerability to injuries like ulcers or erosions.
• Interestingly, the addition of pepsin or taurocholic acid to the mucosal bath solution at a neutral pH of 7.4 did not significantly affect the bioelectric variables. This demonstrates that these compounds do not inherently weaken the tissue’s electric stability at standard pH conditions.
• No synergistic effect was detected between pepsin or taurocholic acid and mucosal acidification. This signifies that the combined actions of pepsin or taurocholic acid with increased acidity do not amplify the adverse effects on tissue’s bioelectric properties.

Study Conclusions

• In conclusion, the researchers discovered that acidification of the stomach mucosa, with or without pepsin or taurocholic acid, resulted in reduced tissue resistance. This could potentially be a risk factor for the development of squamous erosions or ulcers in horses.
• These findings reinforce the belief that such gastric conditions in horses could be instigated, partly, by prolonged exposure of their gastric squamous mucosa to stomach acid.