1 Introduction, General Aims, and Scope.- 2 Historical Background.- 2.1. Early Studies of Phosphorus Metabolism.- 2.2. Hydrolysis of Phosphate Esters.- 2.3. Identification of Phosphatases as a Separate Group of Enzymes.- 2.4. Nomenclature.- 2.5. Robert Robison and His Collaborators.- 2.6. Early Experiments Concerning Solubilization and Purification.- 2.7. Properties of Alkaline Phosphatases.- 2.8. Phosphatase Assays.- 2.9. Reaction Mechanisms.- 2.10. Microbiological Studies.- 2.11. Early Clinical Applications.- 2.12. Histochemistry.- 2.13. Procedures for the Separation of Alkaline Phosphatase Isoenzymes.- 2.14. Function.- References.- 3 Distribution in Nature.- 3.1. Introduction.- 3.2. Plants.- 3.3. Algae.- 3.4. Slime Molds.- 3.5. Bacteria.- 3.6. Fungi.- 3.7. Protozoa.- 3.8. Cnidaria (= Coelenterates) and Ctenophora.- 3.9. Platyhelminthes.- 3.10. Nemertina.- 3.11. Phylum Aschelminthes: Class Nematoda.- 3.12. Acanthocephala.- 3.13. Annelids.- 3.14. Molluscs.- 3.15. Arthropoda.- 3.16. Phoronida.- 3.17. Echinodermata.- 3.18. Vertebrates.- 3.19. Vertebrates: Individual “Systems”.- References.- 4 Purification.- 4.1. Introduction.- 4.2. Preliminary Treatment of Living Organisms to Increase Yield.- 4.3. Preparation and Storage of Starting Material.- 4.4. Disruption of Cells.- 4.5. Subcellular Fractionation as a Preparative Step.- 4.6. Solubilization of the Enzyme.- 4.7. Removal of Water and Unwanted Reagents.- 4.8. Fractionation by Column Techniques.- 4.9. Other Methods of Fractionation.- 4.10. Assessment of the Progress of Purification.- 4.11. Crystallization.- 4.12. Final Product.- 4.13. Comparison of States of Purity of Different Alkaline Phosphatase Preparations.- 4.14. Conclusion.- References.- 5 Structural Features.- 5.1. Introduction.- 5.2. Amino Acid Composition.- 5.3. Amino Acid Sequences.- 5.4. Substitution of Amino Acids.- 5.5. Metals.- 5.6. Carbohydrates.- 5.7. Inorganic Phosphate.- 5.8. Interconversion of Molecular Species.- 5.9. Molecular Weights.- 5.10. Chemical and Physical Modification of Alkaline Phosphatases.- 5.11. Physical and Chemical Probes of Internal Structures.- 5.12. Summary.- References.- 6 Reaction Mechanisms.- 6.1. Introduction.- 6.2. Compounds of Phosphorus.- 6.3. Nonenzymatic Hydrolysis.- 6.4. Substrates of Alkaline Phosphatases.- 6.5. Steps of the Alkaline-Phosphatase-Catalyzed Reaction.- 6.6. Rate-Limiting Factors.- 6.7. Hydrolysis and Transphosphorylation.- 6.8. Ionic Strength and Alkaline Phosphatase Kinetics.- 6.9. Metals and Alkaline Phosphatase Kinetics.- 6.10. Effect of Hydrogen Ion Concentration: Why “Alkaline” Phosphatase?.- 6.11. Inhibition of Alkaline Phosphatases.- 6.12. Some Unresolved Problems Concerning Reaction Mechanisms.- References.- 7 Measurement of Alkaline Phosphatase Activity.- 7.1. Introduction.- 7.2. Enzyme Sample.- 7.3. Substrates.- 7.4. pH “Optimum”.- 7.5. Buffers.- 7.6. Other Components in the Reaction Mixture.- 7.7. Inhibitors.- 7.8. Reaction Temperature.- 7.9. Sample and Reaction Volumes; Reaction Containers.- 7.10. Time Course of the Alkaline Phosphatase Reaction.- 7.11. Reaction Products and Their Measurement.- 7.12. Analytical Variability.- 7.13. Measurement of Alkaline Phosphatase Activity Based on Nonoptical Determinations.- 7.14. Methods of Expressing Activity.- 7.15. Measurement of Alkaline Phosphatase Concentration by Immunological Techniques.- References.- 8 Isoenzymes.- 8.1. Introduction.- 8.2. Methods Available for the Separation and Identification of Alkaline Phosphatase Isoenzymes.- 8.3. Bacterial Alkaline Phosphatases.- 8.4. Fungi.- 8.5. Slime Molds.- 8.6. Cnidaria.- 8.7. Platyhelminthes.- 8.8. Nemertina.- 8.9. Acanthocephala.- 8.10. Annelids.- 8.11. Molluscs.- 8.12. Arthropods.- 8.13. Echinoderms.- 8.14. Isoenzymes within Vertebrate Tissues.- 8.15. Isoenzymes in Blood Plasma.- 8.16. Conclusions.- References.- 9 Clinical Utilization of Alkaline Phosphatase Measurements.- 9.1. Introduction.- 9.2. Reference Values.- 9.3. Associations with Human Disorders.- 9.4. Skin and Subcutaneous Tissues.- 9.5. Breast.- 9.6. Hemopoietic and Lymphatic Systems.- 9.7. Bone.- 9.8. Joints.- 9.9. Muscle.- 9.10. Adipose, Fibrous, and Other Connective Tissues.- 9.11. Respiratory System.- 9.12. Cardiovascular System.- 9.13. Digestive System.- 9.14. Liver and Biliary Tract.- 9.15. Pancreas.- 9.16. Urinary System.- 9.17. Male Reproductive System.- 9.18. Female Reproductive System.- 9.19. Endocrine System.- 9.20. Nervous System.- 9.21. Brief Aids for Resolving Unexpected Results.- 9.22. Summary.- References.- 10 Utilization of Alkaline Phosphatase Measurements in Veterinary Practice.- 10.1. Introduction.- 10.2. Dogs.- 10.3. Cats.- 10.4. Horses.- 10.5. Cattle.- 10.6. Sheep.- 10.7. Pigs.- 10.8. Goats.- 10.9. Rats.- 10.10. Mice.- 10.11. Guinea Pigs.- 10.12. Hamsters.- 10.13. Rabbits.- 10.14. Nonhuman Primates.- 10.15. Miscellaneous Eutherian Mammals.- 10.16. Marsupials.- 10.17. Birds.- 10.18. Amphibians, Reptiles, and Fish.- References.- 11 Industrial and Other Uses.- 11.1. Use in the Dairy Industry.- 11.2. Use in the Identification and Classification of Microorganisms.- 11.3. Use as an Analytical Reagent.- 11.4. Industrial Uses.- 11.5. Use in the Assessment of Soil and Water Samples.- 11.6. Use in the Measurement of Plasma Volume.- 11.7. Use in the Detection of Fecal Matter.- 11.8. Use in Enzyme-Linked Immunosorbent Assays (ELISA).- 11.9. Use in Biological Assays.- References.- 12 Physiological Functions.- 12.1. Introduction.- 12.2. Enzymatic Activity as a Clue to Function.- 12.3. Distribution in Nature as a Clue to Function.- 12.4. Embryonic Development as a Clue to Function.- 12.5. Transport of Specific Substances as a Possible Function.- 12.6. Hydrolysis of Intracellular Metabolites as a Possible Function.- 12.7. Role in Phagocytosis.- 12.8. Role in Calcification Mechanisms.- 12.9. Induction of Alkaline Phosphatases.- 12.10. Denervation Experiments.- 12.11. Role in the Development of Cancer.- 12.12. Conclusions Regarding the Physiological Functions of Alkaline Phosphatases.- References.- Appendix: Procedures.- A.1. Introduction.- A.2. Manual Reference Method: Continuous Spectrophotometric Measurement of Total Alkaline Phosphatase Activity in Human Serum.- A.3. Manual Sampling Method: Measurement of Total Alkaline Phosphatase Activity in Human Serum.- A.4. Automated Continuous-Flow Method: Measurement of Total Alkaline Phosphatase Activity in Human Serum.- A.5. Automated Continuous-Flow Micromethod: Automated Fluorometric Method for Alkaline Phosphatase Microassay.- A.6. Leukocyte Staining Method: Cytochemical Method for Straining Granulocytic Leukocytes for Leukocyte Alkaline Phosphatase Activity (LAPA).- References.