Animal Science 434 Reproductive Physiology Endocrinology: Part B
Mechanism of Hormone Action
Mechanism of Hormone Action
Receptor Structure
Mechanism of Hormone Action Protein Hormones (cAMP second messenger) LH G Receptor Plasma Membrane Adenylate Cyclase C R Protein Kinase A (PKA) S-ER Steroid Synthesis Mitochondria Nucleus DNA R-ER Protein Synthesis Protein Synthesis (Enzymes)
Mechanism of Hormone Action Protein Hormones (cAMP second messenger) LH G Receptor Plasma Membrane Adenylate Cyclase ATP cAMP C R cAMP C R Protein Kinase A (PKA) S-ER Steroid Synthesis Mitochondria Nucleus DNA R-ER Protein Synthesis Protein Synthesis (Enzymes)
Mechanism of Hormone Action Protein Hormones (cAMP second messenger) LH G Receptor Plasma Membrane Adenylate Cyclase C R cAMP ATP cAMP Protein Kinase A (PKA) S-ER Steroid Synthesis (+ PO4) Mitochondria Nucleus DNA Histones mRNA R-ER Protein Synthesis Protein Synthesis (Enzymes)
Mechanism of Hormone Action Protein Hormones (cAMP second messenger) Testosterone LH G Receptor Plasma Membrane Adenylate Cyclase C R cAMP ATP cAMP Protein Kinase A (PKA) S-ER Steroid Synthesis (+ PO4) Mitochondria Pregnenolone Cholesterol Nucleus DNA Histones Cholesterol mRNA R-ER Protein Synthesis Protein Synthesis (Enzymes)
Mechanism of Hormone Action Protein Hormones (cAMP second messenger) Testosterone LH G Receptor Plasma Membrane Adenylate Cyclase C R cAMP ATP cAMP Protein Kinase A (PKA) S-ER Steroid Synthesis (+ PO4) Mitochondria Pregnenolone Cholesterol Nucleus DNA Histones Cholesterol mRNA R-ER Protein Synthesis Protein Synthesis (Enzymes)
cAMP Second Messenger Hormones Anterior Pituitary Hormones LH, FSH, Prolactin STH, ACTH, TSH Placental Hormones HCG, eCG
Protein Hormones (Ca2+ Second Messenger) GnRH G-protein Plasma Membrane Receptor PIP2 PLC R Protein Kinase C Ca2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane
Protein Hormones (Ca2+ Second Messenger) GnRH G-protein Plasma Membrane PIP2 PIP2 Receptor PLC R Protein Kinase C Ca2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane
Protein Hormones (Ca2+ Second Messenger) GnRH G-protein Plasma Membrane PIP2 PIP2 DAG IP3 Receptor PLC Protein Kinase C R R Ca2+ Ca2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane
Protein Hormones (Ca2+ Second Messenger) GnRH G-protein Plasma Membrane PIP2 PIP2 DAG IP3 Receptor PLC Protein Kinase C R R Ca2+ Ca2+ Secretory Granules Endoplasmic Reticulum Plasma Membrane
Protein Hormones (Ca2+ Second Messenger) GnRH G-protein Plasma Membrane PIP2 PIP2 DAG IP3 Receptor PLC Protein Kinase C R R Ca2+ Ca2+ LH Fusion Secretory Granules Endoplasmic Reticulum Plasma Membrane
Calcium Second Messenger Hormones GnRH triggers release of LH in anterior pituitary Oxytocin triggers contractions of smooth muscle PGF2 triggers apoptosis of cell inhibition of progesterone synthesis
Steroid Hormone Action (Slow) (estrogen) Diffusion? Cell Membrane Change in Cell Physiology Cytoplasm Nucleus New Protein Receptor DNA mRNA R-ER Protein synthesis
Steroid Hormone Mechanism Estradiol Progesterone Testosterone, Dihydrotestosterone Cortisol
Steroid Hormone (Fast) Ca2+ (cAMP second messenger) Estradiol G Receptor Plasma Membrane Adenylate Cyclase C R cAMP ATP cAMP Protein Kinase A (PKA) Ca2+ (+ PO4) Smooth Muscle Contraction (Uterine Myometrial Cell) Nucleus DNA Histones mRNA R-ER Protein Synthesis Protein Synthesis (Enzymes)
Steroid Hormone (Fast) Not the classical mechanism of action of a steroid hormone Requires plasma membrane receptor Operates via protein kinase activation Estradiol – smooth muscle of uterus
{ Feedback Loops [ ] - - Hypothalamus Neuro-secretory Cells Releasing Hormones Polypeptides Portal Vein - Anterior Pituitary - Gonadotropins: FSH, LH Proteins Blood Stream Gonads [ Why only effects on Receptor on Cell Surface ] target organs Cyclic AMP inside cell Testosterone { Steroid Hormone Production Estradiol Progesterone Blood Stream Bound to Protein
Endocrine Feedback Loops Negative gonadal steriods Testosterone, Progesterone, Estradiol Protein hormones inhibin Positive Gonadal steroids estradiol
Chapter 5 of Textbook Contains more than covered here Responsible for all material in book Also Handout 4 (found in lecture outline)