[Determination of cytoplasmic receptors for specific steroid hormones. III) Progestin receptor].
A method for determining cytoplasmic progesterone receptor was standardized in normal human endometrium comparing two different tracers, 3H-progesterone (3H-P) and 3H-medroxyprogesterone acetate (3H-MAP), a synthetic progestin which does not bind to Corticosteroid Binding Globulin (CBG). Receptor assays were performed as previously reported for 17beta-estradiol receptor, with slight modifications: incubation lasted 1 hr at 0 degree C, followed by 5 min DCC exposure under the same conditions. When 3H-P was employed as tracer, blanks performed with cold MAP gave similar results as using cortisol in incubation tubes and progesterone and cortisol in blanks. 3H-MAP was a good tracer for progesterone receptor because it neither bound to CBG nor to androgen or cortisol receptors; it had very high affinity and specificity for P-R; it was not metabolized by cytosol at 0 degree C and, finally, it detected receptor amounts quite comparable to those obtained using 3H-P.
De Giovanni
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Istituto di Cancerologia dell'Università di Bologna.
Nicoletti
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Galli
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Nanni
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D000465:Algorithms; D003593:Cytoplasm / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry*; D004717:Endometrium; D005260:Female; D012739:Gonadal Steroid Hormones / Q000032:analysis; D006801:Humans; D007553:Isotope Labeling; D011980:Receptors, Progesterone / Q000032:analysis*
D012739:Gonadal Steroid Hormones; D011980:Receptors, Progesterone