AbstractsBiology & Animal Science

The protein hormone, prolactin, has been of great interest to endocrinologists ever since the demonstration of its presence in the anterior pituitary by Stricker and Grueter in 1929. The action of this hormone was shown to be exerted on the fully developed mammary gland, causing the induction and maintenance of lactation (Nelson, 1936). This role of the hormone has even been of economic interest since prolactin for a time was used in Britian to prevent the decline in the spring in milk production of cows. More recently, there have been reports that prolactin may have other effects in the body besides its function in lactation. It is thought to induce the secretion of hormones from the corpus luteum; but here again, only when the gland is fully developed and ready to function. In 1947 when the present problem was undertaken, almost nothing was known about the behavior of the hormone in the animal body. Questions such as “where does it go, and what does it do?” could not have been answered. The search for answers to questions like this are a proper responsibility of modern endocrinology. As tools for investigations of this nature, radioactive isotopes are proving indispensible, because use of them allows study of the behavior of the hormones in minute doses, and these potent biological entities exert widespread effects when present in almost infinitisimal amounts.[...]