Influence of running different distances on renal glomerular and tubular impairment in humans.

Strenuous exercise has been claimed to modify renal glomerular and tubular function, the relative involvement of the two sites being unknown. These changes may be assessed by the determination of plasma high and low molecular mass proteins. A group of 13 man performed five runs (100, 400, 800, 1,500, 3,000 m) at maximal speed. The excretion rates and renal clearances of creatinine, albumin (Alb), beta 2-microglobulin (beta 2-m) and retinol-binding protein (RBP) were determined before and after each run. The glomerular filtration rate remained stable during the shorter runs and declined by about 40% during the longer runs. The excretion rate for Alb rose from 10-fold above the basal value (6 micrograms.min-1) for the 100 m to 49-fold for the 800 m and then declined for distances up to 3,000 m. The beta 2-m and RBP had a lesser initial increase, 3.5-(rest 55 ng.min-1) and 7.6-(rest 116 ng.min-1) fold, respectively, for the 100 m run and thereafter showed a higher excretion rate than Alb for the 400 m and 800 m runs. The renal clearances of these high (Alb) and low molecular mass (beta 2-m and RBP) proteins followed the changes observed for excretion rates. There was a linear relationship (r2 = 0.996) between plasma lactate concentration and total protein excretion in the postexercise period when taking all five runs into consideration. Glomerular permeability was primarily affected by the 100-m run while the longer runs modified both the glomerular and the tubular sites. To conclude, the present study demonstrated a differential response of the kidney to strenuous exercise with respect to the intensity and duration of the events.