d‐Fenfluramine/prolactin response throughout the menstrual cycle: evidence for an oestrogen‐induced alteration

Abstract

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.

Comparison of the Effects of Citalopram and Escitalopram on 5-Ht-Mediated Neuroendocrine Responses

“…Although the ANOVA showed no main or interactive effects of gender, the sample size was too small to draw firm conclusions about whether or not endocrine responses to citalopram and escitalopram differ between men and women. A potential influence of the menstrual cycle on SSRI-mediated cortisol release also requires further study (O'Keane et al, 1991).…”

Retest Reliability of Prolactin Response to dl-Fenfluramine Challenge in Adults

“…The temporal stability of individual differences in these indices of serotonergic responsivity was examined with Pearson correlations, computed across the 6-month interval. Among women, the challenges were performed without control for menstrual cycle phase, and, because PRL response to fenfluramine is known to vary appreciably across the menstrual cycle (O'Keane et al 1991), the correlations were repeated excluding premenopausal women and post-menopausal women taking hormone replacement therapy according to a cyclic schedule ( n ϭ 15).…”

Discriminating Depression, Physical and Social Anhedonia by Neurotransmitter Related Challenge Tests

“…The inclusion of females would have destroyed the design, because hormone responses partly depend on the phase of the menstrual cycle (Arato & Bagby, 1998;O'Keane et al, 1991), which would have created unequal phases of measurement in the fourfold cross-over design. Furthermore, if results obtained in young healthy males are comparable to those obtained with the same challenge tests in an older predominantly female population of depressed patients, this would rather corroborate than obscure the relationships between transmitter related responses and depression related personality dimensions.…”