Postexercise proteinuria in humans and its adrenergic component.
BACKGROUND
Postexercise proteinuria is a common phenomenon depending on hypothetical mechanisms such as the hemodynamic system and its sympathetic component. To test this hypothesis we administrated an a2-adrenergic agonist (clonidine) in order to reduce the catecholamine response during exercise.


METHODS
Clonidine (300 mg) and a placebo, one week apart, were administrated randomly to nine healthy male subjects (23 yrs age) 2 hours prior to a maximal exercise test on bicycle ergometer. Blood samples and urine collections were obtained at rest and after exercise. Lactate in plasma, creatinine and albumin in plasma and urine were assayed and their clearances were calculated.


RESULTS
Postexercise lactate was identical under placebo and clonidine administration (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 mg.min-1) and albuminuria (71.8 +/- 16.3 versus 116.8 +/- 34.2 mg.min-1) when compared to the placebo test. The postexercise renal clearance of albumin did show a reduction of 40% under the influence of clonidine.


CONCLUSIONS
It may be argued that the catecholamines are partially acting on the mechanisms of the enhanced permeability of the glomerular membrane induced by strenuous exercise.
Poortmans
J R
JR
Chimie Physiologique, Institut Supérieur d Education Physique et de Kinésithérapie, Université Libre de Bruxelles, Bruxelles, Belgium. jrpoortm@ulb.ac.be
Haggenmacher
C
C
Vanderstraeten
J
J
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D000419:Albuminuria / Q000378:metabolism; D000704:Analysis of Variance; D002395:Catecholamines / Q000378:metabolism*; D003000:Clonidine / Q000494:pharmacology*; D003404:Creatinine / Q000097:blood / Q000652:urine; D015444:Exercise / Q000502:physiology*; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D011507:Proteinuria / Q000378:metabolism*; D012709:Serum Albumin / Q000378:metabolism; D018709:Statistics, Nonparametric
D000318:Adrenergic beta-Agonists; D002395:Catecholamines; D012709:Serum Albumin; D019344:Lactic Acid; D003404:Creatinine; D003000:Clonidine