Calcium in Human Biology

Calcium in Human Biology provides an authoritative review of current knowledge and points the way to further progress in the understanding of this essential nutrient. In addition to considering the established importance of an adequate dietary source of available calcium for the formation of sound bones and teeth, there is detailed discussion of the part calcium plays in a variety of aspects of human metabolism. The book is written primarily for those working in the nutritional sciences and related fields. It will also be of interest to clinicians, nutritionists, and to those interested more generally in the biological sciences, as well as to those in the important sectors of the food industry which utilise or produce dairy products and other foods significant to the supply of dietary calcium.

Contenu

1. Chemistry and Biochemistry of Calcium.- Evolutionary Aspects of Calcium.- Chemical Properties.- Extracellular Calcium.- Intracellular Calcium.- Calcium as a Second (or Third?) Messenger.- Calcium Ionophores.- Calcium Antagonists.- Calcium in Other Living Organisms.- 2. Calcium-Regulating Hormones: Vitamin D.- Structure and Synthesis.- Vitamin D Formation in Skin.- Metabolism of Vitamin D.- Regulation of Vitamin D Metabolism.- Vitamin D Function.- Vitamin D Deficiency.- 3. Calcium-Regulating Hormones: Parathyroid Hormone and Calcitonin.- Parathyroid Hormone.- Parathyroid Hormone and the Kidney.- Actions of Parathyroid Hormone on Bone.- Effects in Other Tissues.- Mechanism of Action of Parathyroid Hormone.- Calcitonin.- Physiology of Calcitonin.- 4. Calcium-Regulating Hormones: General.- Adrenal Corticosteroids.- Thyroid Hormone.- Hormones of the Anterior Pituitary Gland.- Insulin.- Sex Steroids.- 5. Gastrointestinal Absorption of Calcium.- Calcium Absorption.- Active Calcium Transport.- Development Aspects.- Analysis of Whole Animal Absorption Studies.- Altering Calcium Absorption.- Therapeutic Considerations.- 6. Renal Excretion of Calcium.- Calcium Excretion.- Form and Measurement of Calcium in Urine.- Expression of Urinary Calcium.- Variation in Daily Calcium Excretion.- Renal Excretion of Calcium.- Regulation of Plasma Calcium by the Kidney.- Hypercalciuria.- Diseases Affecting Urinary Calcium.- 7. Calcified Tissues: Chemistry and Biochemistry.- Introduction: Composition of the Calcified Tissue.- Comparative Histogenesis of the Calcified Tissues.- Calcification Mechanisms.- Remodelling.- Conclusions.- 8. Calcified Tissues: Cellular Dynamics.- Primary Bone Formation.- Postnatal Development of Bone.- Internal Reorganization.- Metabolic States Mainly Characterized by Altered Bone Turnover.- Metabolic States Mainly Characterized by Disturbed Osteoid Mineralization.- Metabolic States Mainly Characterized by a Reduction in Bone Mass.- 9. Calcified Tissues: Structure-Function Relationships.- Macroanatomy.- Age-Related Changes in Bone Mass.- Age-Related Fracture and Osteoporosis.- Bone Mass and Risk of Fractures.- Identification of Those at Risk for Fractures.- Treatment of Osteoporosis.- 10. Calcium in Extracellular Fluid: Homeostasis.- Plasma Calcium Homeostasis.- Effects of Non-nutritional Factors on Plasma Calcium Homeostasis.- Effects of Nutritional Factors on Plasma Calcium Homeostasis.- 11. Calcium as an Intracellular Regulator.- Intracellular Calcium and Cell Behaviour.- The Cell Biology of Intracellular Calcium.- The Evidence for Calcium as an Intracellular Regulator.- How to Measure Free Calcium in Living Cells.- The Source of Intracellular Calcium for Cell Activation.- How Calcium Acts.- The Pathology of Intracellular Calcium.- Pharmacology of Intracellular Ca2+.- Perspectives.- 12. Cellular Calcium: Muscle.- Historical Survey of Calcium Research in Muscle.- Troponin.- Myosin-Linked Regulation.- Ca2+ Regulation in Smooth Muscle.- Actomyosin in Non-muscle Tissue.- Excitation-Contraction Coupling.- Ca2+ Control of Metabolic Processes in Muscle.- Calcium Antagonists.- 13. Cellular Calcium: Nervous System.- Regulation of Intracellular Calcium in Nerve Cells.- Physiological Role of Intracellular Calcium in Nerve Cells.- Summary and Conclusions.- 14. Cellular Calcium: Secretion of Hormones.- Evidence that Calcium Participates in Secretion.- Calcium Fluxes in Endocrine Cells.- Targets for Cytosolic Ca2+.- Concluding Remarks.- 15. Cellular Calcium: Action of Hormones.- Control of Intracellular Calcium.- Modulation of Intracellular Free Ca2+ Concentrations.- Calmodulin and Other Calcium-Binding Proteins.- The Phosphoinositide Cycle.- G Proteins Linking Receptors to Enzyme Activation.- Phospholipase C Activation and Phosphoinositide Second Messengers.- Hormone-Stimulated Ca2+ Fluxes.- Diacylglycerol and Protein Kinase C.- Physiological and Biochemical Responses to Ca2+- Mobilizing Agonists in Selected Systems.- Epilogue.- 16. Cellular Calcium: Cell Growth and Difentiation.- Extracellular Calcium and Cellular Calcium Requirement.- Intracellular Calcium and Calcium Influx.- Calmodulin and Other Calcium-Binding Proteins.- Calcium and Cyclic Nucleotides.- Phospholipid and Protein Phosphorylation.- Calcium and Immune Function.- Oncogenes and Growth Factors.- Bone Cell Differentiation.- Calcium-Regulating Hormones.- Calcium Deficiency and Neoplasia.- Summary.- 17. Dietary Requirements for Calcium.- Calcium Absorption.- Calcium Excretion.- Effects of Calcium Deficiency.- Calcium Requirements and Recommended Allowances.- Comparison with Current Intakes and Recommended Allowances Worldwide.