Progesterone receptors in feline mammary adenocarcinomas.
Estradiol and progesterone receptors were measured in tumor cytosols from 3 intact and 4 neutered female cats with spontaneously occurring mammary adenocarcinomas. Serum from 2 of the intact cats which had been in estrus 4 and 4 to 6 weeks before tumor excision contained progesterone concentrations of 16.2 and 2.2 ng/ml, respectively; serum progesterone in the other cats was less than 2 ng/ml. Estradiol receptors were not detected in any cytosols. Progesterone receptors were detected in all of the cytosols, in concentrations ranging from 4.0 to 11.7 (mean = 7.2) fmol/mg of protein. Scatchard plot analysis of tumor cytosol from an 8th cat with mammary adenocarcinoma revealed presence of high affinity progesterone binding with a dissociation constant (Kd) of 3.47 nM. Tumor receptor content could not be correlated with stage of the estrous cycle nor with whether the cat was intact or neutered.
D000230:Adenocarcinoma / Q000032:analysis / Q000662:veterinary*; D000818:Animals; D001943:Breast Neoplasms / Q000032:analysis; D002371:Cat Diseases / Q000097:blood*; D002415:Cats; D003600:Cytosol / Q000032:analysis*; D004283:Dog Diseases; D004285:Dogs; D005260:Female; D006801:Humans; D008321:Mammary Glands, Animal; D009369:Neoplasms / Q000032:analysis / Q000662:veterinary*; D011374:Progesterone / Q000097:blood; D011959:Receptors, Estradiol; D011960:Receptors, Estrogen / Q000032:analysis; D011965:Receptors, Glucocorticoid / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis*
D011959:Receptors, Estradiol; D011960:Receptors, Estrogen; D011965:Receptors, Glucocorticoid; D011980:Receptors, Progesterone; D011374:Progesterone