title: Different types of steroids inhibit [3H]diprenorphine binding in mouse brain membranes.
abstract: 1. The binding of 60 drugs, mainly steroids, to opioid receptors was studied in crude membrane fractions from mouse brains. 2. Competition assays with the different drugs (5 x 10(-7)-10(-4)M) were performed by labeling opiate receptors with [3H]diprenorphine (0.3-0.4 nM). 3. Only 7 drugs (alpha,5beta-tetrahydrodeoxycorticosterone, megestrol acetate, mifepristone, 17alpha-ethynylestradiol, diethylstilbestrol, clomiphene citrate and tamoxifen citrate) inhibited [3H]diprenorphine binding more than 50% at the highest concentration assayed (10(-4) M). The IC50 values ranged between 6x10(-5) M. 4. Thus, the present results show that only a limited number of steroids, from diverse classes, bind to opiate receptors.
authors.affiliation: Departamento de Medicina, Facultad de Medicina, Oviedo, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Gutiérrez
authors.forename: L
authors.initials: L
authors.lastname: Menéndez
authors.forename: R
authors.initials: R
authors.lastname: Brieva
authors.forename: A
authors.initials: A
authors.lastname: Hidalgo
authors.forename: A
authors.initials: A
authors.lastname: Baamonde
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D004174:Diprenorphine / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes; D051379:Mice; D009292:Narcotic Antagonists / Q000378:metabolism*; D013256:Steroids / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D009292:Narcotic Antagonists; D013256:Steroids; D004174:Diprenorphine