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

This research investigates the causes of gastric ulcers in horses by comparing damage to the stomach lining caused by hydrochloric acid and volatile fatty acids. The study discusses how these acids affect the function of the stomach lining, suggesting their role in ulcer development.

Methodology

• The researchers examined the gastric tissues from 30 horses, specifically the nonglandular gastric mucosa. This is the part of the stomach lining that does not produce acid.
• A laboratory apparatus called an Ussing chamber was used to test the effect of hydrochloric acid and volatile fatty acids (acetic, propionic, and butyric acids) on these tissues.
• Measurement metrics included short-circuit current (Isc), potential difference, and calculated electrical resistance. These were assessed after adding the acids to normal Ringer’s solution (NRS), a solution used to mimic the body’s natural fluids.
• Finally, tissues were examined under a microscope for a detailed view of any changes.

Results

• The study revealed that exposure to hydrochloric acid resulted in a significant decrease in Isc, as compared with tissue samples exposed to NRS at pH 4.0 or 7.0.
• Adding acetic, propionic, and butyric acids (at lower pH levels of 4.0 or 1.5) also caused an immediate significant decrease in Isc.
• Furthermore, a recovery of sodium transport, an indicator of tissue health, was only observed in samples exposed to acetic acid at pH 4.0. Other samples exposed to volatile fatty acids did not show this recovery.

Conclusions

• The results suggest that both hydrochloric acid and the volatile fatty acids can damage the protective function of the non-glandular region of the horse’s stomach, leading to potential ulcer development.
• The researchers conclude that the acids’ impact was due to the fact they can penetrate cells in the stomach lining when in an undissociated form, resulting in cell acidification, hindrance of sodium transport, and cellular swelling.
• Additionally, the study proposes that hydrochloric acid, alone or in combination with volatile fatty acids, under acidic pH may play a pivotal role in the development of gastric ulcers in horses.