Estrogen receptor in normal and neoplastic mouse mammary tissues.

apparent correlation between the susceptibility of a strain to mammary tumor development and the ability of its normal mammary gland receptors to bind estradici. The receptor appears to be in the parenchyma! elements of the gland. The spontaneous mammary tumor showed binding capacities significantly lower than the normal gland, based on wet weight tissue and DNA content. There is no correlation between the binding capacity of a tumor and that of the normal glands from the same strain. Spontaneous mammary tumors appeared to maintain whatever receptor binding capacity they had, when transplanted for one generation into normal or ovariectomized syngeneic hosts.