Regulation of Anterior Pituitary Hormones

Thyrotropin-releasing hormone (TRH)

Promotes secretion of thyroid-stimulating hormone and prolactin

Corticotropin-releasing hormone (CRH)

Promotes secretion of adrenocorticotropic hormone

Gonadotropin-releasing hormone (GnRH)

Promotes secretion of follicle-stimulating hormone and luteinizing hormone

Growth hormone-releasing hormone (GHRH)

Promotes secretion of growth hormone

Growth hormone-inhibiting hormone (GHIH) (somatostatin)

Inhibits secretion of growth hormone and thyroid-stimulating hormone

Prolactin-inhibiting hormone (PIH) (and/or Dopamine (DA))

Inhibits secretion of prolactin

Follicle-stimulating hormone (FSH)

Female: growth of ovarian follicles and secretion of estrogen; Male: sperm production

Luteinizing hormone (LH)

Female: ovulation, production and maintenance of corpus luteum; Male: testosterone secretion

Thyroid-stimulating hormone (TSH)

Growth of thyroid, secretion of thyroid hormone

Adrenocorticotropic hormone (ACTH)

Growth of adrenal cortex, secretion of glucocorticoids

Prolactin (PRL)

Female: milk synthesis; Male: increased LH sensitivity and testosterone secretion

Growth hormone (GH)

Widespread tissue growth, especially in the stated tissues

Antidiuretic hormone (ADH)

Water retention

Oxytocin (OT)

Labor contractions, milk release; possibly involved in ejaculation, sperm transport in the female, sexual affection, and parent-offspring bonding

Thymopoietin, thymosin, thymulin

Stimulate T lymphocyte development and activity

Thyroxine (T4) and triiodothyronine (T3)

Elevate metabolic rate and heat production; promote alertness, quicker reflexes, enhanced absorption of dietary carbohydrates, protein synthesis, fetal and childhood growth, and CNS development

Calcitonin

Promotes net deposition of bone by inhibiting osteoclasts; reduces blood Ca²+ level

Epinephrine, norepinephrine, dopamine

Adaptive responses to arousal and stress

Aldosterone

Promotes Na+ retention and K+ excretion; maintains blood pressure and volume

cortisol and corticosterone

stimulate fat and protein catabolism, gluconeogenesis, stress resistance, and tissue repair

Androgens

growth of pubic and axillary hair, bone growth, sex drive, male prenatal development

Parathyroid hormone (PTH)

Increases blood Ca²+ level by stimulating bone resorption, calcitriol synthesis, and intestinal Ca²+ absorption, and reducing urinary Ca²+ excretion

Insulin

Stimulates glucose and amino acid uptake; lowers blood glucose level; promotes glycogen, fat, and protein synthesis

Glucagon

Stimulates glucose synthesis, glycogen and fat breakdown, release of glucose and fatty acids into circulation

Somatostatin

Inhibits digestion and nutrient absorption; inhibits glucagon and insulin secretion

Amylin

Enhances action of insulin; helps regulate gastric emptying and bile secretion

Calcidiol

Precursor of calcitriol (see kidneys)

Angiotensinogen

Precursor of angiotensin II (see kidneys)

Erythropoietin

Promotes red blood cell production

Hepcidin

Promotes iron absorption

Insulin-like growth factor I

Mediates action of growth hormone

Calcitriol

Increases blood calcium level mainly by promoting intestinal absorption of dietary calcium

Angiotensinogen I

precursor for angiotensin II, a vasoconstrictor

Natriuretic peptides

Lower blood volume and pressure by promoting Na+ and water loss

Gastrin

Acid secretion

Cholecystokinin

Bile release; appetite suppression

Ghrelin

Sensation of hunger; initiation of feeding

Peptide YY

Sense of satiety; termination of feeding