Kinetics and haematological effects of erythropoietin in horses.
A plasma kinetic study of erythropoietin (EPO) was carried out in 4 horses after subcutaneous administration (30 IU/kg bwt) of recombinant human erythropoietin (rhEPO). At standardized intervals for 48 h before injection and for 60 h post-administration, the EPO plasma levels were determined with an immunoradiometric assay based on a sandwich technique. The peak plasma concentration (30-113 mIU/ml) was observed after a delay ranging from 6 to 9 h post-administration and the drug levels reached a physiological value around 60 h following rhEPO injection. Moreover, reference values for plasma EPO concentrations, which were separately determined in 70 racehorses and 34 sport equines, ranged between 0 and 9 mlU/ml. After drug administration, no significant variations in red blood cell count, haemoglobin concentration, haematocrit or mean red blood cell volume were observed in the 4 animals. Further, minimal variations in these parameters were detected in a horse which received three 120 IU rhEPO/kg bwt doses successively. Therefore, high rhEPO doses are probably required to induce a visible haematological effect in equine species.
Jaussaud
P
P
INRA-ENVL, Laboratoire de Toxicologie Métabolique, Ecole Vétérinaire de Lyon, Marcy-l'Etoile, France.
Audran
M
M
Gareau
R L
RL
Souillard
A
A
Chavanet
I
I
D000818:Animals; D004906:Erythrocyte Count / Q000187:drug effects / Q000662:veterinary; D004921:Erythropoietin / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D005260:Female; D006736:Horses / Q000097:blood*; D008297:Male; D011994:Recombinant Proteins / Q000493:pharmacokinetics / Q000494:pharmacology
D011994:Recombinant Proteins; D004921:Erythropoietin