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Hormonal regulation of breast development and lactogenesis. Mammary gland development is initiated at puberty through the action of estradiol and
growth factors and is further regulated during pregnancy through the effects of prolactin and human placental lactogen (hPL). Throughout pregnancy,
progesterone inhibits lactogenesis. This inhibitory effect is removed following parturition, when prolactin levels act unopposed to stimulate lactogenesis.
Suckling, through neuroendocrine reflexes stimulates the release of oxytocin from the posterior pituitary, producing the milk “let-down” reflex. Ductal
elongation is mediated by estrogen, growth hormone (GH), insulin-like growth factor 1 (IGF-1), and epidermal growth factor (EGF). Ductal branching and
alveolar budding are regulated by progesterone, prolactin, and thyroid hormone. Progesterone stimulates ductal side branching and alveolar development.
Source: Chapter 9. Female Reproductive System, Endocrine Physiology, 4e
Prolactin acts directly on mammary epithelium to induce alveolar development. Both progesterone and prolactin synergize to stimulate proliferation of
Citation: Molina PE. Endocrine Physiology, 4e; 2013 Available at: http://mhmedical.com/ Accessed: August 11, 2017
ductal epithelium
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