title: Prolactin receptors in 7,12-dimethylbenz(a) anthracene-induced mammary tumors following endocrine ablation.
abstract: We have determined the effect of ovariectomy and hypophysectomy on prolactin receptors in 7,12-dimethylbenz(a)anthracene-induced mammary tumors. Growing tumors from intact rats show a wide range in the number of prolactin receptors. Ovariectomy causes a slight (approximately 30%) decrease in receptors regardless of whether tumors regress or continue to grow, while the affinity of the receptor for prolactin remains unchanged. Hypophysectomy, which causes a prompt 10-fold decrease in prolactin receptors in rat liver, causes only a slight reduction in prolactin receptors in tumors from these same animals. We conclude that autonomous and ovariectomy responsive 7,12-dimethylbenz(a)anthracene-induced mammary tumors cannot be distinguished on the basis of prolactin receptor sites and that endocrine regulation of prolactin receptors is distinctly different in normal liver and neoplastic mammary tissue.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D002369:Castration; D003864:Depression, Chemical; D005260:Female; D007016:Hypophysectomy; D008099:Liver / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface
chemical_list: D011956:Receptors, Cell Surface; D015127:9,10-Dimethyl-1,2-benzanthracene; D011388:Prolactin