The activity of mixed function oxidases, estimated by in vivo antipyrine clearance, is similar in horses and camels.

This study indicates that the activity of enzymes involved in drug metabolism, specifically hepatic mixed function oxidases, is similar in horses and camels. This was determined by observing the breakdown and clearance of antipyrine, a marker of liver function, in both animals.

Research Method

• The research examined the activity of hepatic mixed function oxidases, which are enzymes involved in detoxifying and metabolizing drugs and other xenobiotics.
• The pharmacokinetics of antipyrine, a drug mainly metabolized by these enzymes, was studied in both horses and camels (Camelus dromedarius). The behavior of antipyrine in the body, its absorption, distribution, metabolism, and excretion, served as the basis for comparing the activity of the related enzymes in both species.
• Seven camels and five horses were administered a single dose of antipyrine (25 mg/kg) intravenously.

Results

• The obtained data reported several parameters regarding the pharmacokinetics of antipyrine in both horses and camels. These included the drug’s elimination half-life, the apparent volumes of distribution, the volumes of distribution at steady state, the volume of the central compartment of the two-compartment pharmacokinetic model, total body clearances, and the areas under the curves to infinity.
• The elimination half-lives in camels and horses were found to be 3.25 +/- 0.23 hours and 3.09 +/- 0.25 hours, respectively. The closer these values, the more similar the elimination rate of antipyrine, hence the mixed function oxidases activity in both species.
• Other parameters, such as the apparent volumes of distribution, the volumes of distribution at steady state, and the total body clearances were also closely matched in both species.
• The similarity of values across the examined parameters indicated that there was no statistical significance between camels and horses.

Conclusion

• The study concluded that the hepatic mixed function oxidases’ activity is similar in horses and camels. This implies that the rate at which these animals eliminate drugs (represented by antipyrine in the study) and possibly other xenobiotics from their bodies is closely matched. This understanding is important in veterinary medicine for drug dose calculations.