Postexercise proteinuria in humans and its adrenergic component

Background. Postexercise proteinuria is a common phenomenon depending on hy pothetical mechanisms such as the hemodynamic system and its sympathetic co mponent. To test this hypothesis we administrated an alpha (2)-adrenergic a gonist (clonidine) in order to reduce the catecholamine response during exe rcise, Methods, Clonidine (300 mug) and a placebo, one week apart, were administra ted randomly to nine healthy male subjects (23 yrs age) 2 hours prior to a maximal exercise test on bicycle ergometer, Blood samples and urine collect ions were obtained at rest and after exercise. Lactate in plasma, creatinin e and albumin in plasma and urine were assayed and their clearances were ca lculated. Results. Postexercise lactate was identical under placebo and clonidine adm inistration (10.1+/-1.0 versus 11.3+/-1.7 mmol.(-1)). It was observed that the clonidine treatment induced a lesser postexercise proteinuria (213+/-28 versus 298+/-55 mug.min(-1)) and albuminuria (71.8+/-16.3 versus 116.8+/-3 4.2 mug.min(-1)) when compared to the placebo test. The postexercise renal clearance of albumin did show a reduction of 40% under the influence of clo nidine, Conclusions. It may be argued that the catecholamines are partially acting on the mechanisms of the enhanced permeability of the glomerular membrane i nduced by strenuous exercise.