Faculty of Physical Therapy

1. Faculty of Physical Therapy Biochemistry of hormones

2. Outcomes • By the end of the lecture, the students will be able to: • Understanding the structure, function and classification of hormones. • Recognize the Biomedical importance of hormones. • Knowing the pathophysiology conditions related to disturbance in the hormonal levels.

3. Hormones are a chemical subtances that regulate the metabolic pathways (functions and structure) in the glands and tissues. • Chemically, Hormones may be protein, a.a (tyrosine) derivites, steroid. • Goiter is a disease results from thyroid gland shrinkage (enlargement of thyroid gland.

5. Hormones also generally fall into three types: • (1)Peptides • (2)Steroid • (3)Tyrosine-derived hormones • Peptide and protein hormones: (GRH,thyrotropin releasing hormone) • All peptides hormones have 3-14 amino acids • some other hormones are protein in nature (Ex. Human growth hormone) • These protein-like hormones are complex: HGH has 191 amino acids • Steroid hormones (androgens, estrogens, cortisone): • All derived from cholesterol.

6. Hormones classification • Hormones can be classified by: • 1- The location of the action. • 2- the nature of the signal. • 3- the 2nd messenger mediated their action. • 4- Chemical composition. • 5- Solubility properties. • 6- location of receptors.

9. Classification of hormones by mechanism of action Hormones bind to intracellular receptors Hormones bind to cell surface receptors Androgen 2nd messenger cAMP Glucagon Estrogen 2nd messenger cGMP Nitric oxide Thyroid ho. T3, T4 2nd messenger Ca or Phosphatidylinositols Acetyl Choline 2nd messenger is Kinases or phosphatases cascade Insulin

11. Hypothalamic and Pituitary Hormones Hypothalamus Trophic ho. Pituitary gland Influence the metabolic reactions in the targets tissues Regulate functions of endocrine glands

12. Hypothalamic and Pituitary Hormones

13. Hormones of Posterior pituitary gland • Both are short peptide 10 a.a • Vasopressin • Oxytocin • It is called Antdiuretic ho. (ADH). • It accelerate the birth by stimulation the uterine smooth muscle contraction. • It promotes the reabsorption of water from the distal renal tubule. • It increases the blood pressure. • Insufficient • Diabetes insipidus.

14. Hormones of Anterior lobe of pituitary gland

15. Adrenocorticotropic hormone ACTH • Regulate the growth and function of the adrenal cortex. • Increase the synthesis and release of adrenal steroids by enhancing the conversion of cholesterols to pregnenolone • Single polypeptide chain • Structure • Functions • Excess ACTH • Cushing syndrome • -ve Nitrogen, K, PO4 balance. • Hypertension and edema. • Glucose intolerance (overt diabetes mellitus). • Increases plasma fatty acids. • Decreased circulating leukocytes.

16. Prolactin PRL • Essential for initiation and maintenance of lactation in mammals. • Protein • Structure • Functions • Excess PRL • Galactorrhea (milk discharge). • Amenorrhea. • Impotence in male.

17. LH FSH & LH Leydig cells Sertoli cells testosterone germ cells differentiation and maturation Pathophysiology • Hypogonadism (lack of testosterone)

18. TSH • TSH affects on thyroid gland. • within min.; Increases synthesis of T3,T4. • Within days; • increases synthesis of proteins, pohospholipids and nucleic acids. • Increase number and size of thyroid cells. • GlycoProtein • αβdimer • Structure • Functions

19. Hormones of Thyroid gland ThyroxineT3 & T4 Amino acids derivatives hormones

20. Structure of T3 & T4

21. ThyroxineT3 & T4 • Biological importance • Enhance protein synthesis. • Cause +ve nitrogen balance. • Enhance transcription of the GH gene Pathophysiology • Goiter (enlargement of thyroid gland). • Hyperthyroidism (Graves disease); increase apetite, rapid heart rate. • Hypothyroidism; (hypertension, slow heart rate, sleepiness, sensitivity to cold, dry skin).

22. Polypeptides hormones 1-Growth hormone GH • Essential for postnatal growth. • For normal Carbohydrates, lipids, proteins and minerals metabolism • Structure • Single polypeptide chain • Functions • Deficiency • Dwarfism • Gigantism • Excess GH

23. Hormones of Pancreas

24. 2-Insulin • Heterodimeric polypeptide Biological importance • Promote the entry of glucose and amino acids into cells. • Promote the utilization of glucose. • has anabolic effect. • Stimulate protein synthesis. • Decrease blood glucose level. • has lipogenic effect. • stimulate the cell replication. Pathophysiology Diabetes mellitus

26. 3- Glucagon • Single polypeptide chain Biological importance • It opposes the insulin action Pathophysiology Diabetes mellitus

27. Steroid Hormones

30. Cholesterol Pregnenolone Sex Steroid Glucocorticoids Mineralocorticoids estrogen progesterone Androgen

31. sexsteroids Production They are made by the (ovaries or testes) by adrenal glands. • Sex steroids include: • androgens: • testosterone • androstenedione • dihydrotestosterone • estrogens: • estradiol • estrone • estriol • progestagens: • progesterone

32. Cholesterol Pregnenolone Progesterone Estradiol Testosterone

33. Androgens Testosterone & Dihydroxytestosterone (DHT) • Sexual differentiation. • Spermatogenesis. • Development of 2ry sexual organs. • Anabolic metabolism. • Gene regulation. • Male pattern behavior. The testes produce testosterone and spermatozoa Biological importance:

34. Estrogens 17β-Estradiol, estriol Biological importance: • Maturation of germ cells • Developing the tissues that will allow the implantation of of the blastocyst. • Providing the hormonal timing for ovulation. • Maintainenance the pregnancy. • Influence the parturation and lactation. • Development of sexual organs. • Anabolic metabolism. • Gene regulation. • stimulate development of mammary glands and of other femals characteristics.

35. Progesterons Biological importance • reduce the proliferative activity of estrogens on the vaginal epithelium. • convert the uterine epithelium from proliferative to secretory (increase glycogen content). • prepare the uterine for implantation of fertilized ovum. • enhance the development of breast glands • Decrease peripheral blood flow Pathophysiology Turner syndrome 1ry and 2ry Hypogonadism

36. Hormones of Adrenal gland

37. Glucocortisone Cortisol Biological importance • Maintenance normal water balance. • Necessary for maintenance normal blood pressure, cardiac output. • Host defense mechanism. • Suppress immune response. • Affect basal metabolism. • glucose production. • lipolysis. • Protein synthesis.

38. Pathophysiology Insufficiency Addison s disease Excess Cushing Syndrome

39. Mineraloocortisone Aldosterone Biological importance • Retention Na+. • Excretion K+, H+. Pathophysiology Conn ʹs Syndrome

40. Suggesting readings Principles of Biochemistry, Donald J. Voet, Judith G. Voet, Charlotte W. pratt, 3rd ed.405-412. • Harpers Biochemistry, Murray RK, Granner DK, Mayes PM and Rodwell VW. 25th ed. P 534-536, 550-559, 588-606,610-623.