Which hormones must be affected in a 32-year-old woman who complains of irregular menstrual cycles and her physical exam reveals galactorrhea and hyperprolactinemia?

Dopamine-dopamine is also referred to as prolactin inhibiting factor. the vastmajority of hormones produced and secreted by the pituitary are stimulated by anassociated releasing factor secreted by the hypothalamus. however, prolactin is underthe tonic inhibition by dopamine. as levels of dopamine fall, the lactotrophs in thepituitary respond rapidly by actively secreting more prolactin. all of the currentlyprescribed galatagogues, such as domperidone, are dopamine antagonists that act toincrease prolactin secretion, resulting in increased breast milk production.there is some evidence that trh and a prolactin releasing peptide (prrp) maystimulate the secretion of prolactin. however, both of these compounds at physiologicallevels do not appear capable of overcoming the tonic inhibition of dopamine.additionally, trh stimulation of prolactin secretion is almost always accompanied bydecreased levels of dopamine.distracter explanations:1) npy - which is released from the arcuate nucleus - may stimulate the release ofprolactin, and therefore levels would not be decreased.2) nitric oxide (no), in normal levels, has been shown in animal models to inhibitprolactin release. however, there has been no clear consensus on the role (if any) ofchanges in circulating no and changes in prolactin secretion.3) prh would increase, not decrease.4) acetycholine (ach) can stimulate oxytocin release - and therefore could stimulatemilk letdown. however, the role of ach on prolactin is unclear, and therefore this is notthe best answer.