HAPPY NEW YEAR 2014

PROLACTIN

Dr. Laxmikanta Say

General Characteristics Synonym – Lactogenic or Mamotrophic hormone

Synthesis – Acidophilic cells of Ant. Pituitary.

Polypeptide – 198 amino acids

MW – 25,000 Half Life – 20 Min. Normal Serum Level - Female – 6-50 ng/ml plasma

- Male – 6-25 ng/ml plasma

CONTROL OF SECRETION

INCREASED SECRETION

Sleep Exercise & stresses Pregnancy - 250 ng/ml Nursing & breast stimulation Primary hypothyroidism Dopamine antagonist Secretion of pituitary stalk

DECREASED SECRETION

PIF Dopamine Dopamine agonists Serotonin antagonist

ACTIONS OF PROLACTIN

During Pregnancy - milk production

Immediately following Pregnancy

- stimulates galactosyltransferase activity

- low FSH & LH

- antireproductive & antigonadal

- Lactational Amenorrhoea.

LACTATIONAL AMENORRHOEA

Stoppage of menstrual periods Temporary sterility Inhibitory actions of Prolactin on

Gonadotrophins – FSH & LH

Duration Women who don not nurse – 6 weeks Women who nurse regularly – 25-30 weeks (6 months)

HYPERPROLACTINEMIA

Decreased FSH & LH Elevated Serum Prolactin

Females - Galactorrhoea, infertility & amenorrhoea.

Chiari-Frommel Syndrome – Persistence of lactation & amenorrhoea

Males – Hypogonadism

- Decreased spermatogenesis

- Loss of Libido

- Impotence