Fundamentals of Hormone Action Flashcards
What hormones are secreted from the hypothalamus?
- TRH, CRH
- GnRH, GHRH
- Somatostatin
- Dopamine
Hormones secreted from the ovaries?
estradiol and progesterone
What hormones are produced by the placenta?
- human chorionic gonadotrophin (hCG)
- human placental lactogen (hPL)
What hormones are produced by the stomach?
gastrin
What hormones are produced by the small intestine?
cholesystokinin (CCK)
Secretin
Describe production of peptide hormones
Preprohormones are synthesized in ribosomes, converted to prohormones in the ER, and then to mature hormones in the Golgi which are then packaged into secretory vesicles that await stimulus release
What types of hormones use receptor protein tyrosine kinases?
Insulin, IGF-1, Growth hormone, Prolactin
Which hormones work via GCPR cAMP action?
Calcitonin, PTH, Glucagon, and TSH
NOTE: When a messenger binds to the GCPR, the alpha subunit binds to GTP and displaces GDP, which activates it to be able to convert ATP to cAMP, which activates PKA
Which hormones work via GCPR phospholipase C action?
Oxytocin, TRH, and GHRH
NOTE: When a messenger binds to the GCPR, the alpha subunit binds to GTP and displaces GDP, which activates it to be able to activate phospholipase C, which converts PIP2 to IP3 and Diacylglycerol
What types of hormones can enter the cell?
Steroids (passively diffuse) and thyroid hormones (needs a transporter to move into the cytosol)
Notes on endocrine receptors
Often times, there are spare receptors extra from the receptors needed to induce a maximal response.
What is the major pathway of metabolism of hormones?
Most are reduced and hydroxylated in phase I and conjugated in phase II metabolism by the liver and then excreted in bile, but some hormones (especially the calcium homeostasis hormones) are excreted by the urinary system
