Serum erythropoietic activity in the rat around birth.
Using a fetal rat liver cell bioassay, serum erythropoietic activity was tested in non-suckled newborn rats comparatively to 21-day-old rat fetuses at time 0 or after 2 h of surviving. The number of erythroid colonies (CFUe) is significantly greater in cultures with neonatal and fetal rat serum after 2 h of surviving than in cultures with fetal rat serum sampled at time 0. These results suggest a release of erythropoietin or erythropoietin-like substances in response to a short hypoxic phase following the parting of the fetus with the mother and preceding the autonomous oxygenation of the newborn by breathing.
D000818:Animals; D000831:Animals, Newborn / Q000097:blood*; D001681:Biological Assay; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D004921:Erythropoietin / Q000096:biosynthesis / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D005311:Fetal Hypoxia / Q000097:blood; D005333:Fetus / Q000378:metabolism; D008099:Liver; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains
D004921:Erythropoietin