d-fenfluramine/prolactin response throughout the menstrual cycle: evidence for an oestrogen-induced alteration.
The prolactin (PRL) response to fenfluramine (FEN), a serotonin (5-HT) releasing agent, is used as an index of 5-HT sensitivity in studying disorders associated with central 5-HT abnormality. Plasma oestrogen levels are known to augment PRL responses to a variety of stimuli. In order to examine the effect that ovarian steroids have on this response nine, healthy women were tested twice at three time points in the menstrual cycle: early follicular, mid-cycle and late luteal phase with either d-FEN, a more specific 5-HT agent than the racemic mixture, or placebo. Responses to d-FEN were maximal at mid-cycle, lowest during the early follicular phase, with responses premenstrually being intermediate between the two. Responses to placebo did not vary. Plasma oestradiol levels fluctuated in parallel with neuroendocrine responses to d-FEN. The possible mechanisms are discussed, including an effect that oestradiol may exert at central serotonin sites.
O'Keane
V
V
Department of Psychiatry, Trinity College Medical School, St James's Hospital, Dublin, Ireland.
O'Hanlon
M
M
Webb
M
M
Dinan
T
T
D000328:Adult; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000502:physiology*; D005260:Female; D005277:Fenfluramine / Q000494:pharmacology*; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D011388:Prolactin / Q000097:blood*; D011985:Receptors, Serotonin / Q000187:drug effects
D004967:Estrogens; D011985:Receptors, Serotonin; D005277:Fenfluramine; D004958:Estradiol; D011388:Prolactin