Estrogenic and antiestrogenic effects of danazol administration in studies of estradiol receptor binding.
In order to study possible cellular estrogenic and/or antiestrogenic effects of danazol, immature female rats were treated with danazol (10 mg/kg/day) or propylene glycol (control) for 4 days (short-term study) and 14 days (long-term study). Estradiol receptor-binding assays were done on the cytosol fraction of the homogenized uterine tissue of each group. AT saturation levels of substrate, short-term danazol treatment was uterotropic and induced an increase in estradiol receptor concentration and binding (p less than 0.02). Long-term treatment, however, caused a marked decrease in estradiol receptor capacity (p less than 0.001). This disparity of the effect of danazol on estradiol receptors suggests a dose- or duration-dependent mechanism of action in the target tissue that may account for some of the clinical effects seen in patients receiving this drug.
D000818:Animals; D003600:Cytosol / Q000032:analysis; D003613:Danazol / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol; D005260:Female; D011245:Pregnadienes / Q000008:administration & dosage*; D011409:Propylene Glycols / Q000494:pharmacology; D051381:Rats; D011960:Receptors, Estrogen / Q000187:drug effects*; D013997:Time Factors; D014599:Uterus / Q000648:ultrastructure
D011245:Pregnadienes; D011409:Propylene Glycols; D011960:Receptors, Estrogen; D004958:Estradiol; D003613:Danazol