Effects of phenylbutazone on gene expression of cyclooxygenase-1 and -2 in the oral, glandular gastric, and bladder mucosae of healthy horses.

The research examined the impact of phenylbutazone (a type of medication) on certain gene expressions found in the oral, stomach, and bladder tissues of horses. The study found that while these genes were present in the horses’ tissues, the administration of phenylbutazone did not significantly affect their expression.

Methods

• This study involved 12 healthy horses that were split into groups. One group received phenylbutazone, while the other group received a placebo treatment. One horse in the placebo group was later removed from the study.
• The researchers carried out endoscopies on each horse to check for ulcers in the stomach and bladder before and after the experiment. This was done to ensure the tissues were healthy for the collection of biopsy specimens.
• Biopsy specimens were collected from the oral, stomach, and bladder tissues of the horses before and after administering phenylbutazone. This drug was mixed with corn syrup and given to the horses at a dosage of 4.4 mg/kg every 12 hours for a week. The placebo group received corn syrup alone.
• The gene expressions of cyclooxygenase-1 and cyclooxygenase-2 in the biopsy specimens were quantified using PCR techniques before and after the seven-day treatment. The researchers compared the results within and between the groups. Prior to the treatment, the researchers compared gene expressions among tissues from 7 horses.

Results

• All the tissues collected from the horses had expressions of the cyclooxygenase-1 gene. However, the cyclooxygenase-2 gene was only expressed in the stomach and bladder tissues, not in the oral tissues.
• The administration of phenylbutazone did not affect the expressions of either the cyclooxygenase-1 or cyclooxygenase-2 genes in the horses’ tissues.

Conclusions

• The cyclooxygenase-2 gene was naturally expressed in the stomach and bladder tissues, but not in the oral tissues of healthy horses.
• The administration of phenylbutazone, even at its maximum recommended dosage, daily for a week did not affect the expressions of the cyclooxygenase-1 or cyclooxygenase-2 genes in the horses’ tissues.