Effects of anterior pituitary hormones on glucose metabolism by rat mammary gland in vitro.

The influence of prolactin and various other pituitary hormones on the initiation and maintenance of lactation has been the subject of frequent investigations during the past few decades (l-5). Species variation and the complexities inherent in ablation and substitution experiments in tivo have led to a vast and conflicting literature (6). Studies of rat mammary gland slices have indicated that glucose utilization and incorporation into fatty acids increase from gestation to lactation (7, 8), that the hesose monophosphate pathway is operative (9, lo), and that prolactin added in vitro increases tissue respiration (11)) osidation of Cland Q-labeled glucose (12, 13), and incorporation of glucose into lipid (13). The present study demonstrates an effect in vitro of prolactin, adrenocorticotropin, and growth hormone on glucose metabolism of rat mammary gland slices. In addition, the influence of these hormones on glucose metabolism at various stages of physiological activity of mammary tissue are compared.