The excretion of microgram doses of hexoestrol by rabbits and rats

Hormone receptor assays: clinical usefulness in the management of carcinoma of the breast

The revision of the subcellular model of hormone action is described, with an incorporation of potential autocrine mechanisms. A general overview of available assay methodologies considers the major disadvantages of earlier methods and describes in detail the current methodologies (sucrose gradient analysis, dextran-coated charcoal assays, ER-EIA, ERICA). A major concern with clinical correlations of response to hormone receptor levels is the quality assurance of the multicentric programs. Results from national and international programs are considered. The clinical correlations are divided into four major categories: (1) the response to hormone deprivation (oophorectomy or adrenalectomy), (2) the development of specific agents which exploit receptor mechanisms (antiestrogens) or inhibit steroid biosynthesis (aminoglutehimide), (3) the rates of recurrence of tumors following mastectomy, and (4) the correlation of hormone receptors with current adjuvant therapies.

Structure-activity relationships of estrogens

The last 50 years has seen an exponential rise in the published reports about estrogen action. The model to describe the early events in the mechanism of action of estrogens via the estrogen receptor is updated in this paper to incorporate some of the recent data on the subcellular localization of the receptor. New evidence suggests that the receptor is a nuclear protein, so it appears that estrogens must first diffuse into the nuclear compartment to initiate estrogen action via the receptor complex. This review traces the development of potent estrogenic compounds by the study of their structure-activity relationships. Studies of structure-activity relationships in vivo using Allen Doisy or 3-day uterine weight tests can provide much valuable information, but the assays suffer from the complex problems of pharmacokinetics and metabolic transformation. Studies in vitro using primary cultures of rat pituitary or uterine cells to assay the ability of a compound to induce prolactin synthesis or progesterone receptor synthesis, respectively, can provide essential information about the structural requirements for a compound to produce estrogenic effects. Nevertheless, it should be pointed out that studies in vivo are required to determine whether a compound is metabolically activated to an estrogen. Estrogen receptor binding models are presented to describe the changes in a molecule that will predict high affinity for the ligand and agonist, partial agonist and antagonist properties of the ligand-receptor complex. Most estrogenic pesticides and phytoestrogens comform to the predictions of the estrogen receptor binding model.

Bifluranol, a novel fluorinated bibenzyl anti-androgen, its chemistry and disposition in different animal species

The synthesis of bifluranol, a new fluorinated bibenzyl anti-androgen, and of 3H-labelled bifluranol is described. The absorption, distribution and excretion of bifluranol has been studied in mouse, rat, ferret and dog; it is readily absorbed following oral administration, but blood concentrations of the drug are low due to hepatic uptake and biliary excretion. Enterohepatic re-circulation occurs, but the drug is excreted primarily in the faeces and only small amounts appear in urine. This pattern of disposition and excretion is similar to that reported elsewhere for the bibenzyl, hexoestrol, and for the stilbene, diethylstilboestrol.