Stress tolerance test and SDS-PAGE for the analysis of urinary proteins in children and youths.

Excretion of urinary proteins (UP) is an important marker for the evaluation of patients with progressive renal disease. In order to analyze quantitative and qualitative variability of UP in relation to physical activity, we used standardized stress tolerance test and SDS-PAGE. Five urine samples were obtained from each patient at rest, during ordinary daily activity and after physical stress.

Difference between orthostatic and march functional proteinuria by application of stress tolerance test and SDS-PAGE.

We introduced minimal necessary criteria and methods for noninvasive laboratory diagnosis and follow-up of functional proteinuria in youths: stress tolerance test, determination of total urinary proteins (TP) and their separation and identification with gradient SDS-PAGE. Renal functional adaptability in conditions of complete rest, in routine daily activity and after several hours of active physical effort has been evaluated by the tolerance test. Excretory urinary proteins, as the most appropriate markers, were analyzed with noninvasive methods.