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Prolacti

ENDOCRINE PHYSIOLOGY

Prolactin-inhihiting factor (PIF), thought to bc dopamine, modulates prolactin secretion. Elcvatod prolactin levcłs increase PIF secretion and cause feedback inhibition of prolactin secretion (shorl-loop feedback inhibition). Estrogen and TRH slimulate prolactin secretion

Pregnancy    Laclalion

Prolactin, along with GH. estrogen, progeslerone, and adrcnocorticoids, is nccessary for breast development

In pregnancy. elevated prolactin, estrogen, and progesterone increase alveolobular development. I ligh estrogen levels inhibit lactation

Sudden decreasc in estrogen and progesterone m presence of prolactin rcsults in milk production. Oxytocin stimulates milk release

Variations in prolactin lcvcl$ by age or condition

Figurę 8.29 Lactation__

^T*^w 'Ole of prolactin in breast deyelopment, pregnancy, and laclalion inhibitory control of dopamine (PIF), Abbmńtion: CH, Growlh hor-is summarized in Ihis figurę. Although prolactin is under dual hypo- monę.

Ihalamic control, it is unique because its secretion is under the

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