Iohexol Clearance for Determination of Glomerular Filtration Rate in Cynomolgus Monkeys (Macaca fascicularis).

The purpose of this study was to validate a method for determine the glomerular filtration rate (GFR) in healthy cynotholgus monkeys by using iohexol. Eighteen healthy cynomolgus macaque monkeys (age, 4 to 6 y [mean, 5 y]; weight, 2 to 6 kg [mean, 4 kg]) were randomly entered into 3 different doses groups (3 male and 3 female macaques per group) of 30, 60, 90 mg I/kg to receive an intravenous bolus injection of iohexol. Serum iohexol concentrations were determined by using liquid chromatography tandem mass spectrometry, and clearance rate were determined by using WinNonlin software. The GFR value (mean +/- SD) of each dose group was 2.50 +/- 0.321, 2.65 +/- 0.529, and 2.75 +/- 0.385 mL/min/kg. These values did not differ significantly between dose levels or sexes. Iohexol clearance is a simple, precise method that is suitable for the determination of GFR in cynomolgus monkeys.