Early luteal progesterone secretion is related to insulin-like growth factor 1 (IGF-1)

摘要

Formation of corpora lutea (CL) and secretion of progesterone during the early luteal phase (first week after ovulation) occurs independently of lutenizing hormone (LH). Corpora lutea are not sensitive to LH in this period and even hypophysectomy doesnot prevent formation of normally functioning CLs after ovulation. There are other factors that influence the development of CLs and secretion of progesterone in this period (e.g. angiogenic and growth factors). Insulin-like growth factor 1 (IGF-1), forexample, has been shown to stimulate progesterone secretion by luteal cells in vitro. The objective of this paper was to determine whether there is also a relationship in vivo between IGF-1 and progesterone secretion. Data were derived from multiparous(n=12) and primiparous (n=21) sows. Blood samples were taken at 6-12 hour intervals to quantify the postovulatory rise in progesterone. Seventy-two hours after ovulation, the progesterone concentration was estimated by linear fit of progesterone values for individual sows. One blood sample for IGF-1 was taken about one day after ovulation and at least four hours after the last feeding.