Effects of exercise on the isoelectric patterns of erythropoietin.
OBJECTIVE
Recombinant erythropoietin has a strong impact on aerobic power and is therefore one of the most potent doping agents in endurance sports. The anti-doping control of this synthetic hormone relies on the detection, in the urine, of its isoelectric pattern, which differs from that of the corresponding natural hormone, the latter being typically more acidic than the former. However, a small number of natural urinary patterns, referred to as "atypical patterns," are less acidic than the dominant form. Based on anecdotal evidence, the occurrence of such patterns seems to be related to particular strenuous exercises. This study aimed to demonstrate this relation using a strenuous exercise protocol.


METHODS
Seven athletes took part in a training protocol including a series of supramaximal short-duration exercises. Urine and blood samples were collected throughout the protocols.


METHODS
World Cycling Center, Aigle, Switzerland, and research laboratories.


METHODS
Seven top-level athletes (cyclists) were involved in this study.


METHODS
Erythropoietin (EPO) isoelectric patterns were obtained by submitting blood and urine samples to isoelectric focusing. Additional protein dosages were performed.


RESULTS
Supramaximal short-duration exercises induced the transformation of typical urinary natural EPO patterns into atypical ones. None of the obtained atypical patterns fulfilled the 3 criteria mandatory for reporting an adverse analytical finding. Serum EPO patterns were not affected by the exercises that caused the transformation of urinary patterns.


CONCLUSIONS
An exercise-induced transient renal dysfunction is proposed as a hypothetic explanation for these observations that rely on parallel investigations of proteinuria in the same samples.
Lamon
Séverine
S
Laboratoire Suisse d'Analyse du Dopage, Centre Universitaire Romand de Médecine Légale, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Epalinges, Switzerland. severine.lamon@chuv.ch
Martin
Laurent
L
Robinson
Neil
N
Saugy
Martial
M
Ceaurriz
Jacques de
Jd
Lasne
Françoise
F
D000293:Adolescent; D000328:Adult; D004300:Doping in Sports; D004305:Dose-Response Relationship, Drug; D004921:Erythropoietin / Q000097:blood* / Q000652:urine*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007525:Isoelectric Focusing; D008297:Male; D011994:Recombinant Proteins; D015813:Substance Abuse Detection / Q000379:methods*; D013557:Switzerland; D055815:Young Adult
D011994:Recombinant Proteins; D004921:Erythropoietin