• Overview
• Products and catalog numbers
• Using GFR-vivo in vivo
• Application notes and posters
• Citations

Overview

Glomerular filtration rate (GFR) is the gold standard in kidney function assessment and is used to determine progression of kidney disease and drug-induced kidney toxicity. One of the most accepted ways to assess GFR is by measuring the rate of disappearance of labeled inulin from the blood; as inulin is completely filtered at the kidneys’ glomeruli (but neither secreted nor reabsorbed by the tubules), this rate of disappearance is directly proportional to GFR.

GFR-Vivo™ 680 is a near infrared fluorescent inulin based agent that, in combination with fluorescence tomography heart imaging, enables quantitative assessment of renal Glomerular Filtration Rate, as an indicator of renal toxicity or injury.

Products and catalog numbers

Using GFR-Vivo in vivo

In Vivo imaging

The generally recommended procedure for in vivo imaging with GFR-Vivo 680 is administration via either tail vein intravenous injection or retro orbital injection and imaging the chest area immediately at various times points (1, 5, 15, 30, and 45 min) following injection.

The blood half-lives of GFR-Vivo 680 in normal mice are approximately 0.5 and 8.0 min, respectively, for T 1/2 Alpha and T 1/2 Beta. Repeat injection and heart imaging may be performed as early as 24 hours for longitudinal studies, although there is longer term retention in the kidneys.

Figure 1. Kinetic imaging of the heart region of mice after GFR-Vivo 680 IV injection offers a noninvasive approach to quantifying circulating fluorescence. A) A representative mouse scanned by FMT yields heart and blood vessel signal throughout the body. Heart fluorescence is identified and quantified at the indicated imaging times. B) Quantitative results established noninvasively by FMT imaging can be correlated to a parallel study in which mice were serially bled and samples assayed ex vivo in comparison to a standard curve. C) Various pharmacokinetic parameters were assessed using the MicroSoft Excel Add-In PK Solver 2.0.

Figure 2. SKH-1E mice underwent either sham surgery or removal of one kidney to alter total GFR capability. After 3-4 days of recovery, mice were injected IV with 2 nmol of GFR-Vivo 680. A) FMT 4000 imaging of representative mice (i.e. representative of the mean of each group) show defined changes in heart region signal over time. B) Quantitative heart results for all mice, established noninvasively by FMT imaging, yielded kinetic curves showing delayed clearance of GFR-Vivo 680 in uninephrectomized mice. C) Various pharmacokinetic parameters were assessed, revealing qantitative differences in GFR. Asterisk indicates statistically significant difference between Sham and Uninephrectomy groups (p < 0.005).

Application notes and posters

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• emptyApplication Note: An in vivo non-invasive method to determine glomerular filtration rate (GFR) 
• Poster: Novel near Infrared Agent for Noninvasive Imaging and Quantification of Glomerular Filtration Rate in Mice

Citations

Please visit our Citations Library for references using GFR-Vivo on the IVIS or on the FMT.