Exercise-induced proteinuria is attenuated by indomethacin

The role of the prostaglandin (PG) and renin-angiotensin hormonal systems in exercise-induced proteinuria following 30 min of submaximal, steady-state exercise was evaluated. Eight healthy males performed cycle ergometry at 75% of VO2peak on three occasions after the administration of a placebo (PLACEBO), a prostaglandin inhibitor (indomethacin, INDO), and an angiotensin converting enzyme inhibitor (captopril, CAPTO). Urine and blood samples were collected prior to, immediately following exercise, and over 40-min recovery. Data were evaluated for differences among drug treatments and measurement phases. During PLACEBO, exercise increased total protein excretion from 64.9 +/- 9.5 to 408.6 +/- 160.8 micrograms.min-1 (P < 0.05). PG inhibition with INDO significantly attenuated the increased proteinuria due to exercise (149.2 +/- 64.0 micrograms.min-1). The proteinuric response to exercise was not altered by CAPTO. Resting plasma renin activity (PRA) and aldosterone (ALDO) were significantly reduced during the INDO trial. Although the twofold increment in ALDO with exercise remained intact during the INDO trial, the PRA response to exercise was significantly blunted. No treatment differences were observed for mean arterial pressure, sodium excretion, urine flow, or creatinine clearance values during rest or exercise. These results suggest that the proteinuria associated with steady-state exercise is PG dependent and not related to hemodynamic influences.