Milk Ejection resulting from Mechanical Stimulation of Mammary Myoepithelium in the Rabbit

Abstract

THERE is good experimental evidence in the rabbit^1,2 that the normal removal of milk from the maternal mammary glands during suckling depends on a reflex release of oxytocin from the posterior pituitary gland. Histological studies^3,4 indicate that the oxytocin induces contraction of the mammary myoepithelium, which results in the expulsion of the milk stored in the alveoli and ducts. The present experiments, which were carried out with twelve lactating rabbits, disclosed a subsidiary mechanism of milk ejection which may help to explain the small variable amount of milk yielded to the young when posterior pituitary activity is prevented by denervation of this gland, by anæsthesia¹, and by emotional excitement⁵.