Prolactin receptors in 7,12-dimethylbenz (a) anthracene-induced mammary tumors following endocrine ablation
Costlow, M.E.; Buschow, R.A.; Mcguire, W.L.
Cancer Research 36(11 Pt 1): 3941-3943
1976
ISSN/ISBN: 0008-5472 PMID: 184919 Document Number: 109967
The effect of ovariectomy and hypophysectomy was determined on prolactin receptors in 7,12-dimethylbenz(a)anthracene-induced mammary tumors. Growing tumors from intact rats showed a wide range in the number of prolactin receptors. Ovariectomy caused a slight (.apprx. 30%) decrease in receptors regardless of whehter tumors regressed or continued to grow, while the affinity of the receptor for prolactin remained unchanged. Hypophysectomy, which caused a prompt 10-fold decrease in prolactin receptors in rat liver, caused only a slight reduction in prolactin receptors in tumors from these same animals. Autonomous and ovariectomy responsive 7,12-dimethylbenz(a)anthracene-induced mammary tumors probably cannot be distinguished on the basis of prolactin receptor sites and endocrine regulation of prolactin receptors were distinctly different in normal liver and neoplastic mammary tissue.