THE HORMONAL CONTROL OF LACTATION

Abstract

The administration to non-pregnant spayed rabbits of corpus luteum extract (progestin) did not cause proliferation of the mammary gland beyond the stage normally attained at puberty. The continuous presence of corpora lutea in the ovaries, during a period equal to that of normal gestation (brought about by experimental means), was equally ineffective in altering the mammary gland. Administration of extracts of whole sheep''s hypophysis to spayed virgin rabbits caused proliferation of the mammary gland and simultaneous lactation, producing in 2 weeks a condition scarcely distinguishable from that present at the full term of gestation. Previous preparation by action of the corpus luteum was found not to be necessary to this effect.