Prolactin secretion in women during the oestradiol-induced luteinizing hormone surge with or without progesterone.
To study the role of progesterone (P4) in the control of PRL increase during the midcycle LH surge, eight normally ovulating women were treated with i.m. injections of oestradiol benzoate (E2B) every 12 h during the early follicular phase of two different cycles (from cycle days 2 to 4). In the second cycle P4 injections were also given to the women every 12 h starting at the end of the E2B treatment (from cycle days 4 to 6). Circadian periodicity of serum PRL levels during the E2-induced LH surge did not differ significantly between the E2B and the E2B + P4 experiments. Evening PRL levels increased significantly in both experiments with a peak during the LH surge and no significant difference between them. We conclude that administration of P4 to normal women does not alter the increase in PRL secretion during the LH surge induced by exogenous oestrogen. It is suggested that P4 is not involved in the mechanism controlling midcycle PRL secretion.
Messinis
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IE
Department of Obstetrics and Gynaecology, University of Aberdeen, Foresterhill, UK.
Templeton
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AA
D002940:Circadian Rhythm; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood*; D008597:Menstrual Cycle / Q000187:drug effects; D006080:Ovarian Follicle / Q000187:drug effects; D011374:Progesterone / Q000494:pharmacology*; D011388:Prolactin / Q000378:metabolism*; D011863:Radioimmunoassay
D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; C010452:estradiol-17 beta-benzoate