Estrogenic effect of estradiol-sulfamate on the male rat anterior pituitary

Estrogen sulfamates (ES) are used for a new treatment strategy to avoid liv er-hormone and hormone-liver interactions. ES represent new synthetic stero ids having an increased systemic and reduced hepatic estrogenicity when giv en orally [1, 2]. In the present study effects of ES and estradiol-benzoate (EB) on adenohypophyseal (AP) and serum concentrations of prolactin (PRL), luteinizing hormone (LH), and pituitary contents of cAMP and cGMP in the m ale rat are demonstrated. The weight gain of experimental animals treated b y ES, EB or both hormones simultaneously was significantly lower compared t o controls. EB but not ES significantly increased the weight of the AP. The amounts of PRL in the AP and serum were significantly increased after EB a dministration. ES significantly increased only AP content of PRL. EB admini stered simultaneously with ES exhibited an additive effect on the AP plasma concentrations of PRL. The EB or ES significantly decreased AP and serum c oncentrations of LH. ES given simultaneously with EB further decreased AP a nd serum concentrations of LH. After administration of either ES or EB, AP contents of cAMP and cGMP were significantly increased. An additive effect of these estrogens on the cGMP content was found. ES given simultaneously w ith EB further increased cGMP content in the AP but partially inhibited the effect of EB on the AP cAMP content. The present results demonstrate that the effects of ES on the AP content of PRL, LH, cAMP, and cGMP differ from the effects of EB. Whether this is due to lower levels of estradiol after t he administration of ES secondary to its different absorption when compared to EB is unknown. Thus, our data support the concept that the ES has a les ser estrogenic effect on the AP function. (C) 1998 Published by Elsevier Sc ience Ltd. All rights reserved.