16-alpha-ethyl-21-hydroxy-19-nor-4-pregnene-3-20-dione and moxestrol

It is firmly believed that sexual differentiation of the brain is linked with external genital differentiation in timing as an in utero event in the human. An extensive search for oestrogen, androgen and progestin receptors failed to show their presence despite adequate controls in cytosols from human fetal brain of gestational ages 14-20 weeks. It is possible that the receptors are present in levels so low that they are undetectable by present-day methods. Our results would indicate that hormonally influenced in utero brain sexual differentiation is most unlikely to occur as a mid-trimester event.

Topics: Animals; Brain; Brain Chemistry; Cytosol; Diethylstilbestrol; Estradiol; Estradiol Congeners; Estrenes; Ethinyl Estradiol; Female; Gestational Age; Humans; Ligands; Male; Metribolone; Pregnenediones; Progesterone Congeners; Rats; Receptors, Androgen; Receptors, Estrogen; Receptors, Progesterone; Sex Differentiation; Testosterone; Testosterone Congeners

The estrogen and progesterone receptors of several organs of the prenatal cynomolgus macaque and the fetal mouse were studied using a combination of the dextran-coated charcoal technique and high-performance liquid chromatography. This procedure permitted the concurrent measurement of both receptors in minute amounts of tissue. Estrogen receptors, but not progesterone receptors, were found in the fetal monkey and mouse uteri. No estrogen or progesterone receptors were detected in the lungs, liver, kidney, heart, brain, adrenal gland, or limbs of mouse or monkey fetuses. The nonspecific binding of radioactive ORG-2058 was not displaced by unlabeled progesterone, 17 alpha-hydroxyprogesterone caproate, or ORG-2058. Because the steroid receptors that are indispensable mediators of steroid hormone action were absent from the nonreproductive tissues, prenatal development of these organs and tissues cannot be adversely influenced by exposure to estradiol, progesterone, or their synthetic analogues.

Topics: 17 alpha-Hydroxyprogesterone Caproate; Animals; Ethinyl Estradiol; Female; Fetus; Hydroxyprogesterones; Macaca; Macaca fascicularis; Mice; Microchemistry; Myocardium; Pregnancy; Pregnenediones; Progesterone; Receptors, Estrogen; Receptors, Progesterone; Tissue Distribution; Uterus