Mechanism of Hormone Action Mechanism of Hormone Action

Mechanism of Hormone Action

Mechanism of Hormone Action

Receptor Structure

Mechanism of Hormone Action Protein Hormones (c. AMP second messenger) LH Receptor G Plasma Membrane Adenylate Cyclase R C S-ER Protein Kinase A (PKA) Steroid Synthesis Mitochondria Nucleus Protein Synthesis (Enzymes) Synthesis R-ER Protein DNA

Mechanism of Hormone Action Protein Hormones (c. AMP second messenger) LH G Receptor Plasma Membrane Adenylate Cyclase ATP c. AMP S-ER c. AMP R C Protein Kinase A (PKA) Steroid Synthesis Mitochondria Nucleus Protein Synthesis (Enzymes) Synthesis R-ER Protein DNA

Mechanism of Hormone Action Protein Hormones (c. AMP second messenger) LH G Receptor Plasma Membrane Adenylate Cyclase c. AMP ATP R c. AMP Protein Kinase A (PKA) S-ER Steroid Synthesis C (+ PO 4) Mitochondria Histones Nucleus Protein Synthesis (Enzymes) Synthesis R-ER Protein m. RNA DNA

Mechanism of Hormone Action Protein Hormones (c. AMP second messenger) LH G Receptor Plasma Membrane Adenylate Cyclase c. AMP Testosterone ATP R c. AMP Protein Kinase A (PKA) S-ER Steroid Synthesis C (+ PO 4) Mitochondria Cholesterol Pregnenolone Cholesterol Protein Synthesis (Enzymes) Synthesis R-ER Protein m. RNA Histones Nucleus DNA

Mechanism of Hormone Action Protein Hormones (c. AMP second messenger) LH G Receptor Plasma Membrane Adenylate Cyclase c. AMP Testosterone ATP R c. AMP Protein Kinase A (PKA) S-ER Steroid Synthesis C (+ PO 4) Mitochondria Cholesterol Pregnenolone Cholesterol Protein Synthesis (Enzymes) Synthesis R-ER Protein m. RNA Histones Nucleus DNA

c. AMP Second Messenger Hormones • Anterior Pituitary Hormones • Placental Hormones » LH, FSH, Prolactin » STH, ACTH, TSH » HCG, e. CG

Protein Hormones (Ca 2+ Second Messenger) Plasma Membrane Receptor Gn. RH G-protein PIP 2 PLC Protein Kinase C R Ca 2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane

Protein Hormones (Ca 2+ Second Messenger) Plasma Membrane Receptor Gn. RH G-protein PIP 2 PLC Protein Kinase C R Ca 2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane

Protein Hormones (Ca 2+ Second Messenger) Plasma Membrane Receptor Gn. RH G-protein PIP 2 DAG PLC IP 3 Ca 2+ R Ca 2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane Protein Kinase C

Protein Hormones (Ca 2+ Second Messenger) Ca 2+ Plasma Membrane Receptor Gn. RH G-protein PIP 2 DAG PLC IP 3 Ca 2+ R Ca 2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane Protein Kinase C

Protein Hormones (Ca 2+ Second Messenger) Ca 2+ Plasma Membrane Receptor Gn. RH G-protein PIP 2 DAG PLC IP 3 Protein Kinase C Ca 2+ R Ca 2+ Secretory Granules Endoplasmic Reticulum Fusion Plasma Membrane LH

Calcium Second Messenger Hormones • Gn. RH • Oxytocin • PGF 2 » triggers release of LH in anterior pituitary contractions of smooth muscle » triggers apoptosis of cell » inhibition of progesterone synthesis

Steroid Hormone Action Steroid (estrogen) Cell Membrane Diffusion? Change in Cell Physiology Cytoplasm Nucleus New Protein Receptor R-ER m. RNA Protein synthesis DNA

Steroid Hormone Mechanism • • • Estradiol Testosterone, Dihydrotestosterone Cortisol

Hypothalamus Feedback Loops Neuro-secretory Cells Releasing Hormones Polypeptides Portal Vein - Anterior Pituitary Gonadotropins: FSH, LH Proteins Blood Stream Gonads Receptor on Cell Surface only effects on [ Why ] target organs Cyclic AMP inside cell Steroid Hormone Production { Testosterone Estradiol Progesterone Blood Stream Bound to Protein

Endocrine Feedback Loops • Negative » gonadal steriods » Protein hormones – Testosterone, • Progesterone, Estradiol – inhibin Positive » Gonadal steroids – estradiol