Preliminary studies of a canine 13C-aminopyrine demethylation blood test.
The objectives of this study were to determine whether a 13C-aminopyrine demethylation blood test is technically feasible in clinically healthy dogs, whether oral administration of 13C-aminopyrine causes a detectable increase in percent dose/min (PCD) of 13C administered as 13C-aminopyrine and recovered in gas extracted from blood, and whether gas extraction efficiency has an impact on PCD. A dose of 2 mg/kg body weight of 13C-aminopyrine dissolved in deionized water was administered orally to 6 clinically healthy dogs. Blood samples were taken from each dog 0, 30, 60, and 120 min after administration of the 13C-aminopyrine. Carbon dioxide was extracted from blood samples by addition of acid and analyzed by fractional mass spectrometry. None of the 6 dogs showed any side effects after 13C-aminopyrine administration. All 6 dogs showed a measurable increase of the PCD in gas samples extracted from blood samples at 30 min, 60 min, and 120 min after 13C-aminopyrine administration. Coefficients of variation between the triplicate samples were statistically significantly higher for the %CO2, a measure of extraction efficiency, than for PCD values (P < 0.0001). The 13C-aminopyrine demethylation blood test described here is technically feasible. Oral administration of 13C-aminopyrine did not lead to gross side effects in the 6 dogs. Clinically healthy dogs show a measurable increase of PCD in gas extracted from blood samples after oral administration of 13C-aminopyrine. Efficiency of CO2 extraction from blood samples does not have an impact on PCD determined from these blood samples. This test may prove useful to evaluate hepatic function in dogs.
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station 77843-4474, USA.
E M
EM
Moeller
J M
JM
Steiner
D A
DA
Williams
P D
PD
Klein
D000632:Aminopyrine / Q000008:administration & dosage / Q000097:blood* / Q000378:metabolism; D000818:Animals; D002247:Carbon Isotopes; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008107:Liver Diseases / Q000175:diagnosis / Q000662:veterinary*; D008297:Male
D002247:Carbon Isotopes; D000632:Aminopyrine