Clinical Significance
Prolactin is a single chain polypeptide hormone secreted by the anterior pituitary under the control of prolactin- inhibiting factors and prolactin releasing factors. These factors are secreted by the hypothalamus. PRL is also synthesized by the placenta and is present in amniotic fluid. PRL initiates and maintains lactation in females. It also plays a role in regulating gonadal function in both males and females. During pregnancy and post-partum lactation, serum prolactin can rise 10 to 20 fold. Prolactin secretion is pulsatile and also shows a diurnal variation, with the serum concentration increasing during sleep and being lowest, approximately 3 hours after waking. The secretion of prolactin is increased by stress and is dependent upon a womans estrogen status.
