Chapter Ⅵ . Calcium Homeostasis

1. Chapter Ⅵ. Calcium Homeostasis PS Wang/2004.05

2. W.F.Ganong: Review of Medical Physiology 1983 12th Ed. Fig21-2 #1440

3. Remodeling of Bone Bone Marrow or Fibrous Periosteum Mesenchymal Stem Cells Osteoclasts Bone Absorption Osteoblasts Bone Deposition (new bone) Osteocytes PS Wang/2004.05

4. Guyton & Hall : Textbook of Medical Physiology 10th ed.2000 fig.79-4 #365

5. Mechanism of Bone Absorption • Osteoclasts (lysosomes) proteolytic enzymes organic matrix digest or dissolute 2. Osteoclasts acids (citric acid & lactic acid) bone salts solution 3. Bone salts & collagen villi from osteoclasts digestion phagocytosis PS Wang/2004.05

6. M. Azria: The Calcitonins (Physiology and Pharmacology). 1989. fig.34a

7. L.E. Mcdonald: Veterinary Endocrinology and Reproduction. 1976 2nd Ed. fig.4-15 #38

8. W.F. Ganong:Review of Medical Physiology 1983 12th Ed. #1439

9. 9 L.E. Mcdonald: Veterinary Endocrinology and Reproduction. 1976 2nd Ed. #29

10. W.F. Ganong:Review of Medical Physiology 2003 20th Ed. fig.21-9 #187

11. M. E. Hadley: Endocrinology 4th ed. 1996 fig.9.1 #1992

12. W.F.Ganong: Review of Medical Physiology 2003 20th Ed. #188 fig.21-10

13. Guyton & Hall : Textbook of Medical Physiology 10th ed.2000 fig.79-9

14. Functional Cytology of the Parathyroid Gland 1. Chief cells---- secrete PTH 2. Oxyphil cells (1) absent in many animals & in young human beings (2) increase in numbers with advancing age (3) probably age-chief cells (4) poorly developed ER, Golgi apparatus, & secretory granules 3. Transitional oxyphil cells PS Wang/2004.05

15. Biological Effects of PTH 1. blood ［Ca2+］( absorption of Ca2+ & PO4-3 from bone) 2. blood ［PO4-3］( excretion of renal phosphate) 3. urine ［PO4-3］and urine ［Ca2+］ 4. the rate of skeletal remodeling and the net rate of bone resorption 5. osteocytic osteolysis in bone (rapid effect) and the numbers and/or activation of osteoclasts on bone surface (slow phase) 6. urinary excretion of hydroxyproline-containing peptides 7. activation of adenyl cyclase in target cells. 8. formation of active vit. D metabolites by the kidney. PS Wang/2004.05

16. M. E. Hadley: Endocrinology 2nd ed. 1988 fig.9.3 #1993

17. L.E. Mcdonald: Veterinary Endocrinology and Reproduction. 1976 2nd Ed. fig.4-5 #32

18. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. fig.4-6 #33

19. Guyton & Hall : Textbook of Medical Physiology 10th ed.2000 fig.79-10 #367

20. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. fig.4-12 #36 p69

21. W.F.Ganong:Review of Medical Physiology 2003 20th Ed. fig.21-6 #1441

22. Christiansen, C. “New Horizon in Osteoporosis” The Parthenon Publishing Group, Lancs, UK, 1988, pp.15

23. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. Fig.4-18 #41

24. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. Fig.4-23 #42

25. Calcitonin, CT • Source ---(1) in animals :parafollicular cells (C- cells) of thyroid gland (2) in lower animals : C-cells in ultimobranchial glands • Chemistry --- (1) polypeptide, 32 A.A. (2) MW = 3,000 • Effects---(1) hypocalcemia : • ↓activity of osteoclasts (rapid effect) • ↑ osteoblastic activity(transient effect) • ↓ formation of new osteoclasts from the osteoprogenitor cells (prolonged effect) • (2) hypophosphatemia • Regulation of Secretion ---- • (1) blood ［Ca2+］ ↑→↑CT • (2) gastrin, pacreozymin, & glucagon → ↑ CT PS Wang/2004.05

26. W.F.Ganong:Review of Medical Physiology 2003 20th Ed. #1442 fig.21-16

27. W.F.Ganong:Review of Medical Physiology 1983 12th Ed. #1443 fig.21-13

28. W.F.Ganong:Review of Medical Physiology 1983 12th Ed. #189 fig.21-11

29. Comparison of Calcitonin Effects with PTH Effects • PTH ---- slowly, need several hrs. CT ----- rapidly, less than 1 hr. (2) PTH ---- long-term regulation CT ----- short-term regulation PS Wang/2004.05

30. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. #43 p.84

31. W.F.Ganong:Review of Medical Physiology 2003 20th Ed. fig.21-7 #182

32. M. E. Hadley: Endocrinology 2nd ed. 1988 fig. 9.9 #1995

33. M. E. Hadley: Endocrinology 2nd ed. 1988 fig. 9.10 #1996

34. Guyton & Hall : Textbook of Medical Physiology 10th ed.2000 fig.79-6 #366

35. W.F. Ganong:Review of Medical Physiology 1983 12th Ed. Fig. 21-14 #1444

36. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. #44 p.85

37. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. #45 p.86

38. Hyperparathyroidism Secondary Hyperparathyroidism • Tumors • Osteoclasts active • Blood ［Ca++］↑ • Broken bone (decalcification) • Cystic bone (osteoclasts tumors) • Osteoblasts active • Kidney stones (calcium phosphate) ↑ • low Ca2+ diet • pregnancy • lactation blood［Ca2+］［PTH］rickets • osteomalacia PS Wang/2004.05

39. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. #47 p.94

40. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. #48 p.95

41. L.E. Mcdonald:Veterinary Endocrinology and Reproduction. 1976 2nd Ed. #49 p.96

42. Hypoparathyroidism • Symptoms: blood［Ca2+］↓ osteoclasts inactive no. of osteoblasts ↓ bone strong tetany ↑ death • treatment: PTH --- expensive, long-term effects Ab ↑ Vit. D ----↑absorption of Ca2+ from GI & bone ↓rickets (children) PS Wang/2004.05

43. Rickets • Causes --- in children, lack of vit. D blood［Ca2+］ • Symptom---- blood［PO4-3］↓↓↓, blood ［Ca2+］↓ (∵ Parathyroid↑ bone absorption ↑ & PO4- 3 excretion ↑) bone weaker osteoblastic activity ↑, but calcification rate↓ parathyroid gland hyperplasia tetany ↑(when blood ［Ca2+］↓) respiratory spasm death • Treatment ---- (1)↑↑ Ca2+, PO4-3& vit. D in diet (2) exposed to sunlight PS Wang/2004.05

44. Adult Rickets = Osteomalacia • Causes (1) fat absorption ↓ vit. D ↓ ↓ Ca2+ & PO4-3 absorption Osteomalacia (2) kidney damage 1,25-DiOH-CC ↓ PS Wang/2004.05