Endocrine System: General Aspects PDF

의료인공지능 융합인재양성 사업 Endocrine System: General Aspects - 내분비 생리: 총론 - Dept of Physiology Ajou University School of Medicine Endocrine organs Primary endocrine organ hypothalamus, pituitary, thyroid Secondary endocrine organ heart, l...

의료인공지능 융합인재양성 사업 Endocrine System: General Aspects - 내분비 생리: 총론 - Dept of Physiology Ajou University School of Medicine Endocrine organs Primary endocrine organ hypothalamus, pituitary, thyroid Secondary endocrine organ heart, liver, stomach, kidney  호르몬의 일반적 기능  Metabolism  Reproduction  Development and Growth  Adaptation  GI function  Others  Chemical Classes of Hormones  Polypeptide and Protein Hormones Small peptide hormones (TRH and vasopressin), Protein hormones (insulin and growth hormone), Glycoprotein hormones (lutenizing hormone (LH), follicle-stimulating hormone (FSH), TSH)  Steroid Hormones Cholesterol derived; cortisol, aldosterone and sex hormones (estradiol and testosterone)  Amine Hormones Amino acid derived; epinephrine, norepinephrine and thyroxine  Eicosanoids Prostaglandins, Thromboxanes, Leukotrienes Peptide Hormones Many protein hormones undergo modifications during packaging and after they have been secreted, e.g., pre-pro-insulin → pro-insulin → insulin Steroid Hormones Amine Hormones catechol Eicosanoids Arachidonic acid Mechanisms of Action of Hormones Hormone Receptors Specificity: the ability of receptor to bind only one type or limited number of structurally related types of chemical messengers Affinity: the strength with which chemical messenger binds to its receptor Receptor Mediated Signaling  Hormone Hormone Receptor Cell Membrane Transducer Cell Membrane Receptor Second messenger generator Desensitization Effector System(s) Second messenger Effector system(s) Various Mechanisms of Hormone Action Cyclic AMP Steroid Hormone IP3 Mechanism Other Mechanism Mechanism Mechanism ACTH GnRH Glucocorticoids Activation of LH and FSH TRH Estrogen tyrosine kinase TSH GHRH Testosterone Insulin ADH (V2 receptor) Angiotensin II Progesterone IGF-1 HCG ADH (V1 receptor) Aldosterone MSH Oxytocin Vitamin D Cyclic GMP CRH a receptors Thyroid hormone ANP b1 and b2 receptors EDRF Calcitonin PTH Glucagon Regulation of Hormone Action 1. Regulation of Hormone Secretion 2. Regulation of Receptors  Down-regulation and Up-regulation of receptors 3. Hormonal Interaction  Antagonism and Synergism  Permissiveness (협동작용)  Regulation of Hormone Action 1. Regulation of Hormone Secretion (1) Input that control Hormone Secretion  Control by Plasma Concentrations of Mineral Ions or Organic Nutrients  Control by Neurons  Control by Other Hormones: tropic hormone (2) Feedback control  Negative feedback  Positive feedback (3) Circadian regulation  Regulation of Hormone Action 1. Regulation of Hormone Secretion 1) Input that control Hormone Secretion (neural-, humoral-input)  Control by Plasma Concentrations of Mineral Ions or Organic Nutrients  Control by Neurons  Control by Other Hormones: tropic hormone  Control by Plasma Concentrations of Mineral Ions or Organic Nutrients Control by Neurons Control by Other Hormones: tropic hormone Stepwise control Example: Hypothalamic-Pituitary-Adrenal Axis Hypothalamus: Releasing hormone  Anterior Pituitary: Tropic (stimulating) hormone  Adrenal Cortex: Endocrine hormone Primary defect vs Secondary defect 2) Feedback Control Negative feedback vs Positive feedback 3) Circadian Regulation  Regulation of Hormone Action 2. Regulation of Receptors - Down-regulation and Up-regulation of receptors 3. Hormonal Interaction Antagonism and Synergism Permissiveness Antagonism (길항작용) When the effects oppose each other. e.g. Progesterone vs estrogen (for myometrial excitability) Synergism (상승작용) When the combined effect is greater than would be expected from summation alone. e.g. FSH and testosterone (for normal rate of sperm production) Permissiveness (협동작용, 허용작용) When one hormone must be present in adequate amounts for the full exertion of another hormones effect. e.g. Thyroid hormone increases the number of epinephrine receptors