Effect of estrogens on prolactin secretion in transsexual subjects

Abstract

The effect of estrogens on the secretion of prolactin in 8 different groups of transsexual subjects was studied. Two different types of estrogens, estradiol or its conjugate and ethinyl estradiol, were used. Different doses and durations of exposure were employed. Plasma levels of prolactin and SHBG after estrogen exposure were compared with corresponding levels before treatment. Results showed that for estrogens to exert an enhancing effect on the secretion of prolactin, three factors needed to be considered: (i) the absolute concentration of estrogen, (ii) the duration of exposure, and (iii) whether levels of SHBG are sufficiently altered to change the concentration of free estrogen. It appears that there exist both time and dose thresholds for effective enhancement of prolactin secretion by estrogen. Estradiol and its conjugate are more likely to induce hyperprolactinemia than ethinyl estradiol. The reduced effect of the latter is probably related to its ability to induce large and rapid increases in SHBG binding which probably results in unaltered free estrogen concentration. In the light of this study, treatment of male transsexuals with high doses of estradiol in its conjugate forms must be viewed with caution.

Transsexualism in Serbia: A Twenty-Year Follow-Up Study

“…Bosinski et al. reported that only 18.3% of subjects had regular cycles (although the sample size was small with only 18 patients) [13], Pache and Fauser reported that 76% had regular cycles [18] compared to 91% in our study, while Goh and Ratnam[19] reported 100% in 20 FTM transsexuals. Bosinski et al.…”

Endocrine intervention for transsexuals

“…Given the high frequency of occult prolactinoma formation (Molitch, 1997) and the apparent rarity of prolactinoma in genetic males during cross‐sex hormone therapy, a direct link between exogenous oestrogens and prolactinoma induction in humans cannot be drawn. Contrary to early conclusions (Asscheman et al ., 1988; Goh & Ratnam, 1990), safety data about adverse pituitary effects of oestrogens in genetic males are reassuring.…”

Prolactin levels during short- and long-term cross-sex hormone treatment: an observational study in transgender persons

“…Several studies have reported increasing prolactin levels in MtFs during CHT (Asscheman et al., ; Goh & Ratnam, ; Gooren, Harmsen‐Louman, & van Kessel, ; Wierckx et al., ). In addition, 13 cases of prolactinomas have been described in MtFs during CHT (Asscheman et al., ; Bunck et al., ; Cunha et al., ; García‐Malpartida, Martín‐Gorgojo, Rocha, Gómez‐Balaguer, & Hernández‐Mijares, ; Gooren, Assies, Asscheman, de Slegte, & van Kessel, ; Kovacs, Stefaneanu, Ezzat, & Smyth, ; Serri, Noiseux, Robert, & Hardy, ).…”

“…After SRS, in MtFs, anti‐androgens are ceased while other hormonal medication will be continued mostly in the same doses (Coleman et al., ). Although CHT is generally considered to be safe, it may affect various organ systems including the prolactin‐producing pituitary gland (Asscheman, Gooren, Assies, Smits, & de Slegte, ; Goh & Ratnam, ).…”