Age-dependent regulation of sodium-potassium adenosinetriphosphatase and sodium-hydrogen exchanger mRNAs in equine nonglandular mucosa.
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.


METHODS
10 horses (5 < or = 5 years old and 5 > or = 12 years old).


METHODS
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 beta1 subunit of NAKA and the gene for the NHE-3 isoform was determined by means of real-time PCR assays.


RESULTS
For horses < or = 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 > or = 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
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.
Peretich
Amanda L
AL
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
Abbott
Lora L
LL
Andrews
Frank M
FM
Dhar
Madhu S
MS
D000199:Actins / Q000235:genetics; D000818:Animals; D005065:Euthanasia; D005753:Gastric Mucosa / Q000201:enzymology / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D006736:Horses / Q000254:growth & development*; D012333:RNA, Messenger / Q000235:genetics*; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics*; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*
D000199:Actins; D012333:RNA, Messenger; D017923:Sodium-Hydrogen Exchangers; D000254:Sodium-Potassium-Exchanging ATPase