1

Chapter II. Mechanisms of Hormone Action

PS Wang/ 2004.05

2

Mechanism of Hormone Action

1. Peptide hormones2. Steroid hormones

PS Wang/ 2004.05

3

Three categories of second messengers

1. Cyclic nucleotides (cAMP; cGMP)2. Ca2+

3. Phosphatidyl inositol

PS Wang/ 2004.05

4Tepperman Metabolic and Endocrine Physiology 1987 5th ed #1216

5Tepperman Metabolic and Endocrine Physiology 1987 5th ed #1217

6

Hadley Endocrinology 1988 2nd ed #1968

7

Hadley Endocrinology 1988 2nd ed #1969

8

Hadley Endocrinology 1988 2nd ed #1970

9

Hadley Endocrinology 1988 2nd ed #1971

10

Greenspan & Forsham Basic & Clinical Endocrinology 1986 2nd ed #1204

11

Greenspan & Forsham Basic & Clinical Endocrinology 1986 2nd ed #1205

12

Greenspan & Forsham Basic & Clinical Endocrinology 1986 2nd ed #1206

13

Inositol Triphosphate

a novel second messenger in cellular signal transduction

by Berridge, M. J., & Irvine, R. F. from Nature 312: 315-321, 1984.

PS Wang/ 2004.05

14

Phospholipase C (PLC)

Calcium Release

Diacylglycerol (DG, DAG)

#1264

15

McDonald Veterinary Endocrinology and Reproduction 1976 2nd ed #3

16

Brook & Marshall: Essential Endocrinology 2001 4th ed, fig 2-20

17

Brook & Marshall: Essential Endocrinology 2001 4th ed, fig 2-21

18

Brook & Marshall: Essential Endocrinology 2001 4th ed, fig 2-22

19

Prostaglandins (PG)Finding: 1934, by von Euler (Sweden), in human semenStructure: unsaturated fatty acid, 20 CCharacteristics: local hormone, 4 series (E, F, A, & B)Functions:PGE soluble in “ether”∵

PGE1: bronchial dilation; platelet aggregation PGE2: bronchial dilation; abortionPGF soluble in “phosphate” (“fosfat” in Swedish)∵

PGF2α: destruction of CL, induction of labor (late pregnancy) & abortion (early pregnancy)PGA1 vasodilation; diuresis; gastric secretionFunctional mechanisms:PG Ca2+ level muscle contraction or steroid synthesis orantagonizes cAMP action in a variety of tissues PS Wang/ 2004.05

20

#202

21

Tepperman Metabolic and Endocrine Physiology 1987 5th ed #1232

22

Tepperman Metabolic and Endocrine Physiology 1987 5th ed #1233

27

23

Discovery of Leukotrienes 1938 Feldbery & Kellaway

Cobra Venom Dog Lung Bronchoconstrictor Agent (= slow reacting substance,

SRS = leukotrienes) Whose effect lasted much longer than that of histamine

(= fast reacting substance)

1940 Brocklehurst Asthmatic Patients + Pollen Lung SRS (SRS-A, A = Anaphylaxis)

4000 X more powerful than histamine on stimulation of smooth muscle in the tracheobronchial tree

perfused

PS Wang/ 2004.05

24

Tepperman Metabolic and Endocrine Physiology 1987 5th ed #1234