title: Measurement of serum clogestone acetate (AY-11,440) by a radioreceptor assay: a practical approach to the quantitative determination of synthetic progestins.
abstract: A novel method is described for the measurement of nanogram quantities of clogestone acetate (3beta, 17alpha-dihydroxy-6-chloropregna-4,6-dien-20-one 3,17-diacetate) in serum:clogestone acetate (CgAc) is converted to chlormadinone acetate in the presence of wheat germ lipase and hydroxysteroid dehydrogenase. The ketonic steroid formed is then incubated with rat uterine cytosol and 3-H-progesterone. The concentration of 3CgAc is estimated from a standard curve derived by incubating cytosol with 3-H-progesterone and varying amounts of chlormadinone acetate. The statistically validated method has been used for the estimation of serum CgAc in humans and dogs given an oral dose of the steroid. The radioreceptor assay (RRA), has practical advantages over related techniques such as radioimmunoassay (RIA) especially with respect to the developmental work. This is the first time that a quantitative assay of a progestin by the tissue receptor approach has been described.
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D006801:Humans; D008297:Male; D045167:Progesterone Congeners / Q000097:blood*; D011869:Radioligand Assay / Q000379:methods; D051381:Rats; D014316:Tritium
chemical_list: D045167:Progesterone Congeners; D014316:Tritium