title: Effects of prolonged low doses of recombinant human erythropoietin during submaximal and maximal exercise.
abstract: The aim of this study was to characterise the effect of prolonged low doses of recombinant erythropoietin (r-HuEPO) on the responses to submaximal and maximal exercise. Volunteer recreational athletes ( n=21) were divided into three groups: r-HuEPO+intravenous iron (EPO+IV, n=7), r-HuEPO+oral iron (EPO+OR, n=9) and placebo ( n=5). During the 12 week study, r-HuEPO or saline injections were given three times a week for the first 8 weeks and for the final 4 weeks the subjects were monitored but no injections were administered. The r-HuEPO doses were 50 IU x kg(-1) body mass for 3 weeks and 20 IU x kg(-1) body mass for the next 5 weeks. An exercise test comprising three submaximal intensities and then increments to elicit maximal aerobic power (VO2max ) was conducted during weeks 0, 4, 8 and 12. During week 0, the mean intensity of the submaximal stages was 60%, 72% and 81%. Blood taken at rest was analysed twice a week for haematocrit (Hct). The relative increases in at weeks 4, 8 and 12 were 7.7%, 9.7% and 4.5%, respectively, for the EPO+IV group; 6.0%, 4.7% and 3.1% for the EPO+OR group; and -0.5%, -0.1% and -1.0% for the placebo group, where the improvements at week 12 for the EPO+IV and EPO+OR groups remained significantly above week 0 values. The Hct was significantly elevated by 0.06 and 0.07 units at week 3 in the EPO+IV and EPO+OR groups, respectively, and was stable during the 5 weeks of low-dose r-HuEPO. After 8 weeks of r-HuEPO use, plasma lactate concentration tended to be lower at exercise intensities ranging from 60% to 100%. This study confirmed the ability of low doses of r-HuEPO to maintain Hct and at elevated levels.
authors.affiliation: Department of Physiology, Australian Institute of Sport, Canberra, Australia.
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Russell
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gore
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ashenden
authors.forename: Robin
authors.initials: R
authors.lastname: Parisotto
authors.forename: Allan G
authors.initials: AG
authors.lastname: Hahn
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000704:Analysis of Variance; D002245:Carbon Dioxide / Q000032:analysis; D004334:Drug Administration Schedule; D004906:Erythrocyte Count; D004921:Erythropoietin / Q000008:administration & dosage*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000187:drug effects* / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006400:Hematocrit; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007275:Injections, Intravenous; D007501:Iron / Q000008:administration & dosage*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D010919:Placebos; D011994:Recombinant Proteins; D012156:Reticulocytes; D016896:Treatment Outcome
chemical_list: D010919:Placebos; D011994:Recombinant Proteins; D004921:Erythropoietin; D002245:Carbon Dioxide; D019344:Lactic Acid; D007501:Iron