Plasma erythropoietin in newborn lambs

In the present study early postnatal changes in erythropoietin (Epo) level and hemoglobin concentration in 8 lambs were examined. Plasma Epo was estim ated by a monoclonal enzyme-immunoassay ( ELISA), developed for human Epo. In all the lambs, except one, Epo was low, or undetectable, immediately aft er birth. Within 6-12 h after birth, a marked increase in plasma Epo was fo und in 4 of the lambs. Within 3-7 days after birth, Epo was back to low lev els. In the lamb with high Epo levels at birth, drastic decreases were obse rved during the next 6 h. There was no obvious correlation between the hemo globin concentrations and the changes in plasma Epo.