Toxicological effects of recombinant human erythropoietin doping: chronic versus acute aerobic exercise

Abstract

Aims: Compare the toxicological effects of rhEPO on rats under chronic versus acute exercise. Protocol: Male Wistar rat groups for the chronic exercise (swimming) – 10 wks of treatment: – control – sedentary (SE D); – rhEPO – 50 IU/Kg/wk; swimming (EX) – 1 hr, 3 times/wk; EX+EPO. For the extenuating exercise (rhEPO given for 3 wks prior to exercise): – swimming (Swi); – Swi+EPO (50 IU/Kg/wk); – running (Run); – Run+EPO. Blood and tissue samples were assessed for: haematology, catecholamine and serotoninergic measures and redox status. Results: The chronic EX+EPO rats showed higher values of RBC, Htc and Hb vs EX and vs Swi+EPO of the acute sessions. Both chronic and acute swimming showed a remarkable sympathetic and serotonergic activation. rhEPO treatment in chronic training has promoted oxidative stress, in contrast with the antioxidant effect on Swi and Run of acute exercises. Conclusions: rhEPO doping is more deleterious in rats mimicking high-performance athletes (chronic training) than in occasional consumers (acute sessions), due to increased CV risk