Increased progesterone receptor concentrations in bladder lesions of estrogen-treated Syrian hamsters.
During studies of renal tumorigenesis induced by estrogen in Syrian hamsters, we have observed that about 15 to 20% of animals develop bladder lesions with an increased wet weight of tissue from 0.2 g to 0.4 to 1.7 g. Histological examination of the lesions showed a spectrum of changes from inflammatory reactions to squamous metaplasia and intense hyperplasia of the transitional epithelium. The concentration of progesterone-binding sites was increased in the bladders with lesions. No specific progesterone-binding sites could be detected in the cytosol of bladders from hamsters not treated with estrogen. The affinity constant for the progesterone-binding sites in cytosol from bladders with lesions was 10(9) M-1, the same as that reported for progesterone receptors in other target tissues for estrogen. The binding sites are specific for progesterone and are not competed for by 17 beta-estradiol, 5 alpha-dihydrotestosterone, or aldosterone.
D000450:Aldosterone / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D006224:Cricetinae; D003600:Cytosol / Q000378:metabolism; D013196:Dihydrotestosterone / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D004967:Estrogens / Q000633:toxicity*; D006965:Hyperplasia / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism; D008297:Male; D008647:Mesocricetus; D008679:Metaplasia / Q000378:metabolism; D011980:Receptors, Progesterone / Q000032:analysis*; D001745:Urinary Bladder Diseases / Q000139:chemically induced* / Q000473:pathology
D004967:Estrogens; D011980:Receptors, Progesterone; D013196:Dihydrotestosterone; D000450:Aldosterone; D004958:Estradiol