Abstract
Objective—To determine whether expression of mRNA for sodium-potassium adenosine-triphosphatase (NAKA) and sodium-hydrogen exchanger (NHE) in samples of the nonglandular portion of the equine gastric mucosa was altered by exposure to volatile fatty acids (VFAs) in an acidic environment.
Animals—10 horses (5 ≤ 5 years old and 5 ≥ 12 years old).
Procedures—Samples of the nonglandular portion of the gastric mucosa were collected and exposed in Ussing chambers to Ringer's solution (control samples), Ringer's solution containing a mixture of VFAs (pH, 1.5 or 4.0), or Ringer's solution containing acetic acid (pH, 1.5 or 4.0). Expression of mRNA for the gene for the β1 subunit of NAKA and the gene for the NHE-3 isoform was determined by means of real-time PCR assays.
Results—For horses ≤ 5 years old, relative expression of mRNA for NAKA was significantly decreased and expression of mRNA for NHE was significantly increased following exposure to the mixture of VFAs or acetic acid, compared with expression in control samples. In contrast, for horses ≥ 12 years old, relative expression of mRNA for both NAKA and NHE was significantly increased following exposure to the mixture of VFAs or acetic acid, compared with expression in control samples.
Conclusions and Clinical Relevance—Results suggested that relative expression of mRNA for NAKA, but not NHE, in samples of the nonglandular portion of the equine gastric mucosa in response to exposure to VFAs in an acidic environment was an age-dependent event.
