Anterior pituitary hormones

6 protein hormones

• Growth hormone (GW)

• Thyroid-stimulating hormone (TSH)

• Adrenocorticotropic hormone (ACTH)

• Follicle-stimulating hormone (FSH)

• Luteinizing hormone (LH)

• Prolactin (PRL)

most activate cyclic AMP second-messenger systems in target cells

tropic hormones

TSH, ACTH, FSH, and LH (regulate hormone secretion of other endocrine glands)

Growth Hormone (GH)

• enhances growth (especially skeletal and bone) by causing cells to uptake nutrients (DNA and protein synthesis), increase rates of growth and proliferation (cell division), make new collagen and extracellular matrix

• anabolic hormone; promotes metabolism and growth

  • increase availability of fatty acids as fuels, increase blood glucose, and uptake amino acids into cells

• homeostasis of GH

  • growth hormone releasing hormone (GHRH)

  • growth hormone inhibiting hormone (GHIH)

  • both from hypothalamus

also called somatotropin

thyroid-stimulating hormone (TSH)

• tropic hormone that stimulates the development and activity of the thyroid gland

• controlled by (BLANK)-releasing hormone (TRH) from the hypothalamus

• rising blood levels of thyroid hormones results in negative feedback that inhibits TSH secretion

also called thyrotropin

adrenocorticotropic hormone (ACTH)

• tropic hormone, stimulates adrenal cortex to release corticosteroid hormones, including glucocorticoids that help resist body stressors

• controlled by corticotropin-releasing hormone (CRH) from hypothalamus

  • levels peak in early morning

• rising blood levels of glucocorticoids feed back and inhibit ACTH secretion

• stressors, including fever and hypoglycemia (low blood sugar), trigger CRH release and therefore increased ACTH secretion

also called corticotropin

gonadotropins

• follicle stimulating hormone (FSH) and luteinizing hormone (LH)

• tropic hormones that regulate gonads (ovaries and testes)

• FSH = eggs and sperm (gamete production)

• LH promotes hormone production in gonads

• control ovarian cycle in women (egg maturation and ovulation)

• gonadotropin-releasing hormone (GnRH) from hypothalamus stimulates gonadotropin release after puberty

• elevated gonadal hormone levels inhibit FSH and LH release

prolactin (PRL)

• Protein hormone, similar in structure to GH

• stimulates milk production in breasts (gross!)

• (blank) release is INHIBITED by (blank)-inhibiting hormone (PIH) from hypothalamus

• elevated estrogen levels, as well as infant suckling after birth, stimulates prolactin release

hypothalamus

• where all the regulating hormones come from (the hormones that act on each of the 6 protein hormones)

• ex. GHRH, GHIH, TRH, CRH, GnRH, PIH