[Creatinine clearance as the foundation for clinical determination of kidney function in swine]

Comparative examinations of renal function using inulin- and endogenous creatinine-clearance tests in 5 pigs showed nearly identical values of glomerular filtration rate (GFR). Based on this relation 79 healthy pigs, weighting 2 kg to 230 kg were investigated using the creatinine-clearance test for determination of normal values of GFR and urine flow rate (Vu) as well as renal excretion (E), renal clearance (Clr) and fractional excretion (FE) of urea, sodium, potassium, calcium, phosphorus, glucose and lactate. The renal excretion of creatinine (E-Creat) was closely correlated with the body weight. Therefore it is possible to use the body weight for estimation of E-Creat and to calculate GFR and Vu using plasma and urine concentrations of creatinine independent of a timed volumetric urine collection. Subsequently E, Clr and FE of electrolytes or other endogenous substances can be evaluated. Finally the practicability of this procedure for detection of disturbed glomerular filtration or tubular reabsorption was demonstrated in piglets suffering from colidiarrhoea and/or transmissible gastroenteritis.