title: Effects of exercise on the isoelectric patterns of erythropoietin.
abstract: 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.
authors.affiliation: 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
authors.forename: Séverine
authors.initials: S
authors.lastname: Lamon
authors.forename: Laurent
authors.initials: L
authors.lastname: Martin
authors.forename: Neil
authors.initials: N
authors.lastname: Robinson
authors.forename: Martial
authors.initials: M
authors.lastname: Saugy
authors.forename: Jacques de
authors.initials: Jd
authors.lastname: Ceaurriz
authors.forename: Françoise
authors.initials: F
authors.lastname: Lasne
mesh_terms: 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
chemical_list: D011994:Recombinant Proteins; D004921:Erythropoietin