Temporal pattern of placental lactogen and progesterone secretion in sheep

• DOI: 10.1038/248435a0
• Publication Date: 2005-08-03T19:59:45Z
• Authors: PAUL A. KELLY; HAMISH A. ROBERTSON; HENRY G. FRIESEN
• Keywords: Placental lactogen; Human placental lactogen

HUMAN and monkey placental lactogens (PL) have been isolated and characterised biologically and chemically1–3 and reports have appeared identifying a placental lactogen in rats4–6, mice7 and goats8. More recently rat serum PL concentrations have been determined quantitatively with a radioreceptor assay9. In the present study we have used the same assay with minor modifications to identify and measure plasma placental lactogen concentrations in sheep during pregnancy and have compared the secretory pattern of this new hormone with plasma concentrations of progesterone and pituitary prolactin.