Comparison of four methods of estimating glomerular filtration rate in cats.
Four methods of evaluating renal function were performed in 6 cats anesthetized with halothane in oxygen. Glomerular filtration rate (GFR) was measured simultaneously in each cat by exogenous creatinine clearance (ECC), bolus inulin clearance, and 99mTc(Sn)-diethylene-triaminepentaacetic acid (DTPA) clearance determined by 2 different methods. In the first DTPA clearance method (DTPA-1), we measured radioactivity in serial blood specimens to construct plasma disappearance curves for calculation of GFR. In the second DTPA clearance method (DTPA-2), we used serial external head counts of radioactivity and a single blood specimen to construct plasma disappearance curves for calculation of GFR. Bolus inulin clearance was calculated from plasma disappearance curves using a 1-compartment open pharmacokinetic model (IN-1) and a 2-compartment open pharmacokinetic model (IN-2). Glomerular filtration rates were measured over 3 hours, for creatinine and DTPA methods, and over 4 hours for the inulin methods. The GFR obtained with the reference method (ECC) was 2.56 +/- 0.61 ml/min/kg of body weight (mean +/- SD). Values for GFR determined by ECC and DTPA-1 were significantly correlated (r = 0.852; P less than or equal to 0.05). Correlation between ECC and DTPA 2 was not as good (r = 0.783; P less than or equal to 0.10), but the 2 DTPA methods significantly correlated with one another (r = 0.897; P less than or equal to 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Rogers
K S
KS
Department of Small Animal Medicine, College of Veterinary Medicine, Texas A&M University, College Station 77843-4474.
Komkov
A
A
Brown
S A
SA
Lees
G E
GE
Hightower
D
D
Russo
E A
EA
D000818:Animals; D001806:Blood Urea Nitrogen; D002415:Cats / Q000502:physiology*; D003404:Creatinine / Q000097:blood / Q000493:pharmacokinetics; D005260:Female; D005919:Glomerular Filtration Rate / Q000662:veterinary*; D007444:Inulin / Q000493:pharmacokinetics; D007668:Kidney / Q000502:physiology*; D008297:Male; D004369:Pentetic Acid / Q000493:pharmacokinetics; D012016:Reference Values; D015203:Reproducibility of Results
D004369:Pentetic Acid; D007444:Inulin; D003404:Creatinine