title: Estimation of glomerular filtration rate in conscious mice using a simplified equation.
abstract: To develop an expedient procedure for estimating glomerular filtration rate (GFR) in conscious mice, we first established a simple technique for repeated blood collections from the tail vein using a microcapillary tube attached to a 24-gauge needle without the hub. Then, we devised a definition equation for estimation of the GFR using the contrast medium iodixanol as a test tracer. Iodixanol was administered as a bolus injection at 1500 mg I/kg to ddY mice, and the GFR was determined by the conventional multisample strategy. Based on cumulative data from the multisample method, an equation for the single-blood-sample method including the iodixanol dose, estimated distribution volume (Vd), and plasma iodixanol concentration at 60 min later was sought. The GFR values from the multisample method were in good agreement with those calculated using the equation. In clinically healthy mice, the GFR decreased gradually with ages from 11 weeks old in both sexes, suggesting the necessity of the corresponding control in each protocol. In nephropathy mice induced by cisplatin, the GFR values decreased with rises in serum BUN and creatinine concentrations, and serum creatinine became elevated when the GFR decreased to approximately 70% of the basal value. The results suggest that the simplified equation using iodixanol, allowing for the repeated use of the same mice, is a versatile procedure for research purposes.
authors.affiliation: Cooperative Department of Veterinary Medicine, Iwate University, Morioka, Iwate, Japan.
authors.forename: Yui
authors.initials: Y
authors.lastname: Sasaki
authors.affiliation: Cooperative Department of Veterinary Medicine, Iwate University, Morioka, Iwate, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Iwama
authors.affiliation: Cooperative Department of Veterinary Medicine, Iwate University, Morioka, Iwate, Japan.
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Sato
authors.affiliation: United Graduate School of Veterinary Science, Gifu University, Gifu, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Heishima
authors.affiliation: Cooperative Department of Veterinary Medicine, Iwate University, Morioka, Iwate, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Shimamura
authors.affiliation: Cooperative Department of Veterinary Medicine, Iwate University, Morioka, Iwate, Japan.
authors.forename: Tosihiro
authors.initials: T
authors.lastname: Ichijo
authors.affiliation: Cooperative Department of Veterinary Medicine, Iwate University, Morioka, Iwate, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Satoh
authors.affiliation: Cooperative Department of Veterinary Medicine, Iwate University, Morioka, Iwate, Japan United Graduate School of Veterinary Science, Gifu University, Gifu, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Furuhama
keywords: Glomerular filtration rate; iodixanol; mice; plasma clearance; renal damage