Endocrine system: Pituitary hormones

THE ENDOCRINE SYSTEM

Endocrinology Pituitary hormones Gonadal hormones Adrenocorticosteroids Thyroid hormones Insulin

The hypothalamus and pituitary gland

The hypothalamus and pituitary gland

Hypothalamic and pituitary hormones

The pituitary gland

Hypothalamic hormones GHRH: Several large peptides with GHRH activity. Rapid increase in plasma growth hormone levels SRIH / Somatostatin: Inhibits release of growth hormones, thyrotropin, glucagon, insulin and gastrin. Short action duration TRH: Stimulates the release of thyrotropin (TSH) CRH: Stimulates secretion of both ACTH and beta-endorphin GnRH/LHRH: Stimulate gonadotropin release PIH, dopamine: Inhibitor of prolactin release

Anterior pituitary hormones GH (somatotropin) TSH: Increases iodine uptake and production of thyroid hormones in thyroid cells ACTH FSH: Glycoprotein that stimulates gametogenesis and follicle development in women, and spermatogenesis in men LH: Major stimulant of gonadal steroid production. Regulates follicular development and ovulation in women Prolactin: Lactation

Posterior pituitary hormones Oxytocin: Synthesized in hypothalamus and transported through cell axons to the posterior pituitary. Stimulant of uterine contraction (labor) and lactation Vasopressin/ADH: Synthesized in hypothalamus and released from the posterior pituitary. Acts on V2 receptors to increase synthesis of water channels, resulting in increased water reabsorption. VP also causes smooth muscle contraction

Hypothalamic and pituitary hormones

The pituitary gland

Pituitary hormones and their targets

Clinically important pituitary hormones Drug Source Action Clinical use SOMATREM Recombinant DNA GH Pituitary deficiency Growth failure OCTREOTIDE Recombinant DNA Somatostatin Acromegaly Excess pituitary activity COSYNTROPIN Recombinant DNA ACTH Corticosteroid substitute Diagnosis of adrenal failure Infant spasms LEUPROLIDE GOSERELIN Recombinant DNA GnRH Gonadal dysfunction Cancer UROFOLLITROPIN Human postmenopausal urine ~FSH Infertility hCG Human pregnant urine ~LH Infertility Cryptorchidism MENOTROPIN (hMG) Human postmenopausal urine ~FSH+LH Infertility BROMOCRIPTINE Ergot alkaloid ~Dopamine Excess lactation Pituitary tumors DESMOPRESSIN Substituted vasopressin Vasopressin Diabetes insipidus Postoperative abdominal distree PITOCIN Recombinant DNA Oxytocin Induction of labor Postpartum bleeding

Clinically important pituitary hormones Drug Action Adverse effects SOMATREM GH Antibodies to GH (do not interfere with activity) OCTREOTIDE Somatostatin COSYNTROPIN ACTH Allergic responses Corticosteroid excess LEUPROLIDE GOSERELIN GnRH UROFOLLITROPIN ~FSH Allergic reactions Arterial embolism hemoperitoneum ovarian hyperstimulation Gynecomastia (males) hCG ~LH MENOTROPIN (hMG) ~FSH+LH BROMOCRIPTINE ~Dopamine Pituitary tumors DESMOPRESSIN Vasopressin GI distress, tremor, sweating, allergies (urticaria), asthma PITOCIN Oxytocin Water intoxication, uterine spasms and rupture, postpartum bleeding, Fetal effects