Kidney iohexol clearance

WB Saunders, Philadelphia, pp 93-123 Finco DR (1997) Kidney function. In Kaneko JJ, Harvey JW, Bruss ML (eds) Clinical Biochemistry of Domestic Animals, 6th edn. Academic Press, San Diego, pp 441—485 Finco DR, Braselton WE, Cooper TA (2001) Relationship between plasma iohexol clearance and urinary exogenous creatinine clearance in dogs. J Vet Intern Med 2001 Jul-Aug 15(4) 368-373... 

P2.m. The cysteine proteinases are one of four major classes of endoproteinases that possess the ability to degrade intact glomerular basement membranes [144]. All nucleated cells produce cystatin at a stable rate. More than 99% is freely filtered by the glomerulus with little secretion or reabsorption. As a result, it has many of the ideal features for use as a marker of kidney function and eshmate of GFR. Serum cystatin C concentrations demonstrate a good inverse correlation with radionuclide derived measurements of GFR and has been shown in several studies to be superior to creatinine and comparable to iohexol clearances in estimating eGFR [145,146]. 

The GFR can be estimated by clearance measurements of endogenous or exogenous small molecules (urea, creatinine, 2-MPT, inulin, cystatin C, iohexol, or iodixanol). An ideal marker of GFR should be primarily excreted by the kidneys, freely filtered by the glomerulus, and neither secreted nor reabsorbed by the tubule. It should also be supplied to the plasma at a constant rate and exhibit no or minimal protein binding. If these criteria are met, such as for inulin, the GFR is equivalent to the renal/urinary clearance of the substance, as defined earlier in this chapter. 

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