Studies on the Physiology of Lactation. Iii. The Reciprocal Hypophyseal-Ovarian Relationship as a Factor in the Control of Lactation†§

Investigations during the past few years by Strieker and Giüter (1929), Corner (1930), Nelson and Pfiffner (1930–31), and Turner and Gardner (1931) have established the relation of the anterior hypophysis to the induction of lactation. These various studies have shown that the mammary glands must be developed under the influence of the ovarian hormones before the anterior lobe factor can initiate secretory activity. The degree of development of the glands which is necessary before lactation may be induced and the relative importance of the two ovarian hormones, oestrin (theelin) and progestin (corporin), in the production of gland growth varies in the different species of animals examined. However, it seems definitely established that the mammary glands of any animal must have attained at least the condition present in the adult female of that species before lactation may be induced by the administration of anterior lobe extracts.