Learning objectives Gain an understanding of Adrenocorticoids affect both carbohydrate metabolism(glucocorticoids) and modulate water balance and Na*/K+ transport(mineralocorticoid) 2. The nature of the stress activated pathways that control adrenocorticoid secretion 3. Structures of the major mineralo-and glucocorticoids 4. Biosynthesis of mineralo-and glucocorticoids 5. Anti-inflammatory effects of glucocorticoids and the use of pharmacological doses for treatment of inflammation 6 Structure-activity relationships for glucocorticoid activity 7. Development of synthetic glucocorticoids with reduced mineralocorticoid activity 8. Toxicity of adrenal corticoids
Learning Objectives Gain an understanding of: 1. Adrenocorticoids affect both carbohydrate metabolism (glucocorticoids) and modulate water balance and Na+ /K+ transport (mineralocorticoid) 2. The nature of the stress activated pathways that control adrenocorticoid secretion 3. Structures of the major mineralo- and glucocorticoids 4. Biosynthesis of mineralo- and glucocorticoids 5. Anti-inflammatory effects of glucocorticoids and the use of pharmacological doses for treatment of inflammation 6 Structure-activity relationships for glucocorticoid activity 7. Development of synthetic glucocorticoids with reduced mineralocorticoid activity 8. Toxicity of adrenal corticoids
ADRENAL CORTICOIDS 1563 Existence of adrenal gland discovered by eustachio 1849 Addison attributed"bronzed skin"disease to malfunctioning Adrenal glands 1856 Brown-Sequard removed adrenals of cats and dogs who promptly died proving properly functioning adrenals essential for survival 1894 Adrenal divided into medulla secreting adrenaline and the cortex 1938 Reichstein isolates 29 new substances from adrenal cortex all are steroids 1948 Kendall isolates pure cortisone 1950 Kendall, Reichstein and Hench awarded Nobel prize for medicine
ADRENAL CORTICOIDS 1563 Existence of adrenal gland discovered by Eustachio 1849 Addison attributed “bronzed skin” disease to malfunctioning Adrenal glands 1856 Brown-Sequard removed adrenals of cats and dogs who promptly died proving properly functioning adrenals essential for survival 1894 Adrenal divided into medulla secreting adrenaline and the cortex. 1938 Reichstein isolates 29 new substances from adrenal cortex all are steroids 1948 Kendall isolates pure cortisone 1950 Kendall, Reichstein and Hench awarded Nobel prize for medicine
HUMAN ORGANS OF THE ENDOCRINE SYSTEM neal hypothalmus Steroid hormones are synthesised 7/pituitary primarily in parathyroid thyroid Adrenal Cortex-Adrenocorticoids lymus Ovaries, testes- Sex steroids stomachs adrena Steroid secretion is generally controlled by peptides secreted from the kidney pancreas duodenum Hypothalmus and pituitary ovary uterus testes
HUMAN ORGANS OF THE ENDOCRINE SYSTEM pineal hypothalmus pituitary parathyroid thyroid thymus stomach adrenal kidney pancreas ovary uterus testes duodenum Steroid hormones are synthesised primarily in Adrenal Cortex - Adrenocorticoids Ovaries , testes - Sex steroids Steroid secretion is generally controlled by peptides secreted from the: Hypothalmus and pituitary
BIOLOGICAL EFFECTS OF ADRENOCORTICOIDS Modulation of carbohydrate metabolism -Glucocorticoids increases levels of glycogen in the liver and circulating glucose early effects stimulate immune system prolonged secretion leads to immune suppression and cell death basal rhythmic secretion increased during periods of stress Modulation of water balance, promotion of Na*/K transport-Mineralocorticoids promotes Nat uptake in tubular epithelial cells nodulates K+ ion transport control of water reabsorption secreted only during periods of stress Glucocorticoid and mineralocorticoid receptors have been discovered and each class of compound can interact with each receptor Secretion of cortisol during stress is essential for life
BIOLOGICAL EFFECTS OF ADRENOCORTICOIDS Modulation of carbohydrate metabolism - Glucocorticoids increases levels of glycogen in the liver and circulating glucose early effects stimulate immune system prolonged secretion leads to immune suppression and cell death basal rhythmic secretion increased during periods of stress Modulation of water balance, promotion of Na+ / K+ transport - Mineralocorticoids promotes Na+ uptake in tubular epithelial cells modulates K+ ion transport control of water reabsorption secreted only during periods of stress Glucocorticoid and mineralocorticoid receptors have been discovered and each class of compound can interact with each receptor Secretion of cortisol during stress is essential for life
STRESS ACTIVATED PATHWAYS Humoral pathway STRESS RAS pathway Limbic system Visceral brain Norepinephrine Endocrine Neuronal pathway Hypothalmus CRF 41 residues Renin Anterior pituitary Fight or flight ACTH 39 residues Angiotensin I & lI Adrenal cortex Adrenal cortex cortisol glycogen Aldosterone GR receptor increased Antinflammatory effects blood ← Sodium uptake cell death pressure
STRESS ACTIVATED PATHWAYS Humoral pathway STRESS Neuronal pathway RAS pathway Limbic system Visceral brain Endocrine Hypothalmus Anterior pituitary Adrenal cortex cortisol (-) (-) (-) CRF 41 residues ACTH 39 residues GR receptor Antiinflammatory effects cell death glycogen Fight or flight Norepinephrine Renin Angiotensin I & II Adrenal cortex Aldosterone Sodium uptake increased blood pressure
MAJOR NATURAL GLUCOCORTICOIDS OH OH HO OH HO Cortisol(hydrocortisone) OH Corticosterone OH Cortisone
MAJOR NATURAL GLUCOCORTICOIDS Cortisol (hydrocortisone) O OH O HO OH Corticosterone O OH O HO O OH O O OH Cortisone
BIOSYNTHESIS OF GLUCOCORTICOIDS o HO "OH HO cholesterol 17a-hydroxy 11B, 17a(OH)2-progesterone pregnenolone e f 0b OH HOCH2-O HOCH2=0 OH oH HO " OH cd HO pregnenolone o 17a-hydroxy 11-deoxycortisol Cortisol b. 17a-hydroxylase progesterone e OH c.5-ene-3β- hydroxy dehydrogenase o C, d d. 3-0X0-4.5-isomerase OH HOCH2YO e. 21-hydroxylase OH f. 11B-hydroxylase HO 17x,21(OH)2 pregnenolone Cortisone
BIOSYNTHESIS OF GLUCOCORTICOIDS HO HO O HO O OH O O OH O HOCH2 O OH O HOCH2 O HO OH O HOCH2 O O OH O O HO OH cholesterol pregnenolone 17a-hydroxypregnenolone 17a-hydroxyprogesterone 11-deoxycortisol Cortisol Cortisone 17a,21(OH)2 - pregnenolone 11b,17a(OH)2 -progesterone OH HO OH O b c,d e f e c,d f e b. 17a-hydroxylase c. 5-ene-3b-hydroxy dehydrogenase d. 3-oxo-4,5-isomerase e. 21-hydroxylase f. 11b-hydroxylase
GLUCOCORTICOID- METABOLISM OH OH Hydrocortisone Oxidation HO OH OH Cortisone o Oxidation/reduction Reduction OH COOH HO H OH HO -OH OH HO HO H 3-keto-A4 and 20-keto reduced Acid metabolites
GLUCOCORTICOID - METABOLISM O HO O OH OH O O O OH OH Cortisone Hydrocortisone Oxidation Reduction OH H OH HO HO HO H 3-keto-D4 and 20-keto reduced COOH OH OH H HO HO H Oxidation/reduction Acid metabolites