Endocrine Mechanisms PDF
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Uploaded by PrudentRainforest
University of Galway
Brendan Higgins
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Summary
These lecture notes cover endocrine mechanisms, including hormone action, receptors, and second messengers. The document includes diagrams and tables that aid in clarifying the information presented. It's suitable for undergraduate physiology students.
Full Transcript
Dr Brendan Higgins Discipline of Physiology Rm 3018, Human Biology Building University [email protected] ofGalway.ie Copyright © Learning Objectives University ofGalway.ie Mechanisms of Ho...
Dr Brendan Higgins Discipline of Physiology Rm 3018, Human Biology Building University [email protected] ofGalway.ie Copyright © Learning Objectives University ofGalway.ie Mechanisms of Hormone Action University ofGalway.ie General example: Thyroid hormone receptor (TR) Control of Hormone Release University ofGalway.ie University ofGalway.ie Nervous System Modulation ↑ University ofGalway.ie Basic Mechanism of Hormone Action University ofGalway.ie One Consequence of Signal Transduction is Amplification University ofGalway.ie Receptors a University ofGalway.ie Receptors IR shares ~50 - 80% homology with ligand-binding & tyrosine kinase domain, respectively, of the IGF-1 receptor (IGF-1R) Oncogenesis 2016 15;5 PMID: 26878387 University ofGalway.ie Receptor Locations University ofGalway.ie Molecular model of growth hormone receptor Peptide Hormone Receptors University ofGalway.ie Ionotrophic Receptor University ofGalway.ie Tyrosine Kinase Receptor University ofGalway.ie Metabotropic Receptor - G-Protein Coupled Receptor a, b, a a University ofGalway.ie Mechanisms of Hormone Action A: Entry of hormone into the target cell, binding to and activation of an intracellular receptor and binding of the receptor—hormone complex to specific DNA sequences to activate or repress gene expression. (HRE, hormone-response element). B: Activation of cell-surface receptors and coupled 2nd-messenger systems, with University variety of intracellular consequences. ofGalway.ie Second Messengers University ofGalway.ie Amino Acid-Based Hormone Action: cAMP Second Messenger Mechanism of adrenaline Universityaction ofGalway.ie https://tinyurl.com/6ezrtr28 Amino Acid-Based Hormone Action: (PIP2) Phospholipase C-Ca2+ 2nd Messenger System a a a a University ofGalway.ie PIP2 2nd Messenger System Alternative Image University ofGalway.ie Diacylglycerol Activation of PKC University ofGalway.ie Inositol-1,4,5-triphosphate and Ca2+ m m University ofGalway.ie Ca2+-Calmodulin Second Messenger System Ca2+ works as a 2nd messenger because intracellular Calmodulin (calcium-modulated protein) [Ca2+] is kept low and tightly regulated by voltage- multifunctional Ca++-binding messenger protein and dependent channels, IP3-gated channels, and intracellular target of 2nd messenger Ca++. Binding of ryanodine receptors Ca++ activates calmodulin, which then modifies its Brief cytosol spikes in [Ca++] have impact interactions with target proteins such as kinases or Exocytosis of secretory vesicles phosphatases. Very important in control of metabolism, Contraction in muscle cells inflammation, immune response, memory etc. University ofGalway.ie https://tinyurl.com/3a4xys8f Steroid Hormones University ofGalway.ie Steroid Hormones: Action University ofGalway.ie Summary of Hormone Mechanisms University ofGalway.ie MCQs University ofGalway.ie MCQs University ofGalway.ie MCQs University ofGalway.ie
