Stimulatory effect of prolactin on human placental progesterone secretion at term in vitro: possible inhibitory effect on oestradiol secretion.
Maternal and fetal circulating prolactin (PRL) increases 10-fold compared with the non-pregnant state. We examined the effect of PRL upon placental steroidogenesis. It had a significant (P less than 0.05) time-dependent stimulatory effect upon placental explants/P4 accumulation and secretion into the medium. The maximal stimulatory effect (two-fold) in dose-dependent experiments was found to be 200 ng/ml. The effect of PRL upon oestradiol secretion was mainly inhibitory. This inhibition was most pronounced at 200 ng/ml. In conclusion, placental steroid secretion is modulated by PRL. This effect occurs mainly at concentrations seen in the placenta at term, suggestive of its physiologic role.
Barnea
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Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa.
Fares
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Shahar
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D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000378:metabolism*; D004965:Estrogen Antagonists / Q000502:physiology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D010920:Placenta / Q000378:metabolism* / Q000502:physiology; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011374:Progesterone / Q000378:metabolism*; D011388:Prolactin / Q000008:administration & dosage / Q000502:physiology*
D004965:Estrogen Antagonists; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin