Involvement of the renin angiotensin system in the pathogenesis of postexercise proteinuria.

Proteinuria after strenuous exercise is common in healthy subjects. The pathophysiologic mechanism of postexercise proteinuria (PEP) is not clear, although the phenomenon has long been known and many explanatory theories have been proposed. It is widely recognized that angiotensin II may increase filtration of protein through the glomerular membrane, and that its concentration in plasma increases during exercise. The aim of this study was to evaluate possible involvement of angiotensin II in the pathogenesis of PEP. Of 25 young volunteers who performed maximal aerobic exercise, eight showed PEP. The exercise was repeated after an interval of at least one week, now 90 minutes after administration of captopril (25 mg). Captopril did not affect the achieved work load of the maximal blood pressure and heart rate during the exercise, but PEP was not found. As it was possible to prevent PEP by administering an angiotensin-converting enzyme inhibitor, the study supports the theory that the renin angiotensin system is involved in the pathogenesis of PEP.