Prolactin receptor in human mammary carcinoma.

The specific binding of labelled human prolactin was determined in 83 human breast carcinomas. Twenty-seven tumors (32.5%) contained specific binding for prolactin of at least 1% and were considered prolactin receptor positive. The binding was found linearly related to membrane protein concentration and specific only for lactogenic hormones. By Scatchard analysis the dissociation constant appeared similar to that observed in other target tissues, with a low binding capacity.