DIABETOGENIC ACTION OF PROLACTIN

Abstract

IT HAS been difficult to establish whether the effects on carbohydrate metabolism of different preparations of prolactin are due to the hori mone itself or to other pituitary hormones which may be present in small amounts in these preparations. Thus, the clearly marked anti-insulin effect of impure pituitary preparations (Young, 1936; Marks, 1936) is reduced so as to be infinitesimal in purified preparations (Young, 1948, b, c). Riddle and his associates, in several papers published between 1937 and 1947, reported that prolactin had hyperglycemic and diabetogenic activity; later they (Riddle et al., 1947) found that prolactin preparations which were free of adrenocorticotropin (ACTH) did not modify the blood sugar of the fasting pigeon, and the slight increase in blood sugar observed in animals which were fed seemed to be due to a greater ingestion of food. Hepatic glycogen, however, was found to be increased by prolactin in normal pigeons, and even more so in hypophysectomized animals.