Posterior Pituitary

Causes of raised prolactin - the p's

• pregnancy
• prolactinoma
• physiological/ increased chest wall stimulation
• polycystic ovarian syndrome
• primary hypothyroidism
• phenothiazines/ haloperidol, metoclopramide, domperidone, verapamil,
• dopamine depleting agents (methyldopa, reserpine), TCAs, SSRIs, narcotics, opioids, cocaine

also 1/3 of acromegaly, stress, exercise, sleep, renal insufficiency

prolactinoma may co-secrete growth hormone (GH)

Hypothyroidism --> increased TRH stimulates prolactin secretion

Verapamil is the only CCB to raise prolactin level.

Prolactin inhibits GNRH. If there is no GNRH, the body cannot release LH and FSH. So,

Women = galactorrhea, amenorrhea, and infertility

Men = erectile dysfunction and decreased libido ;  rarely gynecomastia and galactorrhea

Long-term suppression of sex hormone production by prolactinoma in women can lead to osteoporosis

Non-functioning pituitary adenomas generally arise from gonadotropin-secreting cells of the pituitary gland. Patients usually present with hypogonadism and low gonadotropin levels; serum alpha-subunit levels are characteristically increased. Large tumors may cause symptoms directly through mass effect on local tissues.