Hormone Function Hormone Function • Morphological • Physiological • Metabolic • Chemical Hormone Function • To study a hormone and its action you must know about: – Its origin – Storage – Secretion – Transportation – Mechanism of action – Function – Metabolism – Chemical structure • Best known hormones, insulin, catecholamines, steroids General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Protein/peptide hormones – Cells with much R.E.R. – Protein packaging in the golgi – Merging of vesicles – Movement of vesicles to the membrane • 3 fates – Into blood (endocrine) – Reabsorbed (autocrine) – To a neighboring cell (paracrine) General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Steroid hormones – Cells with much S.E.R. – Acetate cholesterolÆLarger lipids – Coalescence into large granules – Movement of vesicles through the membrane • 3 fates – Into blood (endocrine) – Reabsorbed (autocrine) – To a neighboring cell (paracrine)General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Steroid hormones – Multicellular synthesis – Multitissue synthesis – Noncellular systems General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Prohormones – Large, biologically active precursors (mostly found in protein hormones) – Clevage to active and inactive peptides General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Prohormones – Significance • Hormone storage • Spatial configuration for synthesis • Efficient movement of large amts of protein • Ex. insulin General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Prohormones – Significance of Hormone storage • No degradation • Inactive • Readily available for secretion • Secretion of hormones – Movement of granules to membrane (microtubules) – Ca and energy dependent membrane changes • Hormone Degradation – Liver, kidney, lung – ½ life – Binding proteins General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Binding proteins – Plasma proteins made in the liver – Equilibrium: bound ÅÆ unbound • Functions of binding – Good storage, increases ½ life, blood brain barrier. • Metabolism– ½ lives in minutes – Enzymatic degradation in liver, lung, or kidney – Oxidations, reductions, deaminations, methylations – Sulfate or glucioronic conjugation (water soluable) – Trace amounts in feces General Model for Hormone Biosynthesis Storage,Transport and Metabolism • Each of these processes contributes to the overall level of hormone in the