Renal Handling of Phosphate

1 Indices for the Measurement of the Renal Handling of Phosphate.- 1. Introduction.- 2. Glomerular Filtration and Tubular Transport.- 2.1. The Composition of the Glomerular Filtrate.- 2.2. The Direction of Tubular Transport.- 2.3. The Concept of a Limit or Threshold Concentration.- 3. Threshold Concentration and Splay for Phosphate.- 3.1. The Relation between Maximum Reabsorption and Glomerular Filtration.- 3.2. Splay.- 4. Indices for the Measurement of the Renal Handling of Phosphate.- 4.1. The Renal Threshold Concentration for Phosphate.- 4.2. The Phosphate Clearance.- 4.3. The Reabsorbed or Excreted Fraction of the Load.- 4.4. The Excretion Rate of Phosphate.- 4.5. The Plasma Phosphate Concentration.- 4.6. The Choice between Indices.- 5. References.- 2 Sites of Renal Tubular Reabsorption of Phosphate.- 1. Introduction.- 2. Phosphate Transport between the Glomerulus and the Late Accessible Proximal Convolution of the Superficial Nephron.- 2.1. Phosphate Reabsorption in the Intact Animal.- 2.2. Phosphate Reabsorption in the Absence of Parathyroid Hormone.- 2.3. Phosphate Secretion in the Proximal Tubule.- 3. Phosphate Transport in the Loop.- 3.1. Evaluation by Micropuncture of the Late Accessible Proximal and Early Accessible Distal Convolutions Sampled at Random.- 3.2. Evaluation by Micropuncture of the Late Accessible Proximal and Early Accessible Distal Convolutions of the Same Nephron.- 3.3. Evaluation by Microinjection into the Late Accessible Proximal and Early Accessible Distal Convolutions.- 3.4. Evaluation by in Vivo Microperfusion.- 3.5. Evaluation by in Vitro Microperfusion.- 3.6. Characteristics of Loop Phosphate Reabsorption.- 4. Phosphate Transport in the Terminal Nephron.- 4.1. Evaluation by Micropuncture.- 4.2. Evaluation by Distal Tubular Microperfusion and Microinjection.- 4.3. Possible Sites of Phosphate Reabsorption in the Terminal Nephron.- 5. Conclusions.- 6. References.- 3 Is Phosphate Secreted by the Kidney?.- 1. Introduction.- 2. Phosphate Secretion by Kidneys of Lower Vertebrates.- 2.1. Fishes.- 2.2. Amphibians.- 2.3. Reptiles.- 2.4. Birds.- 2.5. Summary of Phosphate Secretion by Nonmammalian Vertebrates.- 3. Is Phosphate Secreted by the Mammalian Kidney?.- 3.1. Use of Clearance Techniques to Assess Phosphate Secretion by the Mammalian Kidney.- 3.2. Evidence of a Peritubular-to-Luminal Flux of Phosphate in the Mammalian Kidney.- 4. Conclusions.- 5. References.- 4 Cellular Mechanisms of Phosphate Transport.- 1. Introduction.- 2. Transmembrane Movement of Phosphate.- 2.1. Membrane Composition and Structure.- 2.2. Phosphate-Membrane Interactions.- 2.3. Enzymes of the Brush-Border Membrane.- 3. Characteristics of Phosphate Transport.- 4. Nonhormonal Factors.- 4.1. Sodium Dependency of Phosphate Transport.- 4.2. Glucose and Phosphate Transport.- 4.3. Effect of Acid-Base Balance on Phosphate Transport.- 5. Hormonal Regulation of Phosphate at the Cellular Level.- 5.1. Mechanism of Regulation by Cyclic Nucleotides.- 5.2. Other Cellular Mechanisms in Regulation of Phosphate Transport.- 6. References.- 5 The Effects of Parathyroid Hormone on Renal Phosphate Handling.- 1. Introduction.- 2. Effects of PTH in Various Segments of the Nephron.- 2.1. Proximal Convoluted Tubule.- 2.2. Pars Recta-Loop of Henle.- 2.3. Distal Convoluted Tubule and Terminal Nephron.- 13. Mode of Action of PTH.- 4. Mechanism of the Phosphaturie Effect of PTH.- 4.1. Role of Adenyl Cyclase-cAMP System.- 4.2. Role of Inhibition of Sodium Reabsorption-Sodium-Dependent Phosphate Transport Hypothesis.- 4.3. Role of Tubular Fluid Alkalinization.- 5. References.- 6 Effects of Hormones Other than Parathyroid Hormone on Renal Handling of Phosphate.- 1. Introduction.- 2. Growth Hormone (GH).- 2.1. Effects of GH on Serum Pi Levels.- 2.2. Extrarenal Effects of GH on Pi Metabolism.- 2.3. Effects of GH on Renal Handling of Pi.- 2.4. Factors Related to the Effects of GH on Tubular Transport of Pi.- 3. Vasopressin (Antidiuretic Hormone; ADH).- 3. 1. Effects of ADH on Serum Pi Levels.- 3.2. Effects of ADH on Renal Handling of Pi.- 4. Thyroid Hormones (Thyroxine and Triiodothyroine).- 4.1. Effects of Thyroid Hormones on Serum Pi Levels.- 4.2. Extrarenal Effects of Thyroid Hormones on Pi Metabolism.- 4.3. Effects of Thyroid Hormones on Renal Handling of Pi.- 4.4. Factors Related to the Effects of Thyroid Hormones on Renal Handling of Pi.- 5. Calcitonin (CT).- 5.1. Effects of CT on Serum Pi Levels.- 5.2. Extrarenal Effects of CT on Pi Metabolism.- 5.3. Renal Effects of CT.- 5.4. Factors Related to the Effects of CT on Renal Handling of Pi.- 6. Glucagon.- 6.1. Effects of Glucagon on Serum Pi Levels.- 6.2. Effects of Glucagon on Renal Handling of Pi.- 6.3. Factors Related to the Effects of Glucagon on Renal Handling of Pi.- 7. Insulin.- 7.1. Effects of Insulin on Serum Pi Levels.- 7.2. Effects of Insulin on Renal Handling of Pi.- 7.3. Factors Related to the Effects of Insulin on Renal Handling of Pi.- 8. Catecholamines.- 8.1. Effects of Catecholamines on Serum Pi Levels.- 8.2. Effects of Catecholamines on Renal Handling of Pi.- 9. Glucocorticoids.- 9.1. Effects of Glucocorticoids on Serum Pi Levels.- 9.2. Extrarenal Effects of Glucocorticoids on Pi Metabolism.- 9.3. Effects of Glucocorticoids on Renal Handling of Pi.- 9.4. Factors Relating to the Effects of Glucocorticoids on Renal Handling of Pi.- 9.5. Circadian Rhythm of Pi Excretion and Glucocorticoids.- 10. Estrogens.- 10.1. Effects of Estrogens on Serum Pi Levels.- 10.2. Effects of Estrogens on Extrarenal Metabolism of Pi.- 10.3. Effects of Estrogens on Renal Handling of Pi.- 11. Various Other Hormones.- 11.1. Angiotensin II.- 11.2. "Natriuretic Hormone".- 11.3. Prostaglandins (Bartter's Syndrome).- 12. Tumoral Hyperphosphaturia.- 13. References.- 7 Effects of Vitamin D and Its Metabolites on Renal Handling of Phosphate.- 1. Studies in Humans.- 2. Studies in Animals.- 3. Summary.- 4. References.- 8 Effect of Urinary Alkalinization on Renal Phosphate Reabsorption.- 1. Introduction.- 2. Clearance Studies.- 3. Micropuncture Studies.- 4. Microperfusion Studies.- 5. Studies of Luminal Membrane Vesicles.- 6. Theoretical Considerations.- 6.1. Relation between H+ and Phosphate Transport: Phosphate as a Buffer System.- 6.2. Use of Phosphate in Renal Acidification Studies.- 6.3. Physicochemical Properties of Anions.- 6.4. Mechanism of Action of Acetazolamide and Bicarbonate.- 7. Clinical Implications.- 8. References.- 9 Tubular Adaptation to the Supply and Requirement of Phosphate.- 1. Introduction.- 2. Assessment of the Overall Tubular Capacity to Transport Pi.- 3. Tubular Adaptation to the Dietary Supply of Phosphate.- 4. Tubular Adaptation to the Phosphate Demand of the Organism.- 5. Role of l,25(OH)2D3 in the Tubular Adaptation in Pi Transport.- 6. Localization of the Tubular Adaptation in Pi Transport.- 6.1. Influence of Phosphate Supply.- 6.2. Influence of Phosphate Demand through EHDP Treatment.- 7. Tubular Adaptation and Acute Phosphaturic Response to PTH.- 7.1. Influence of Dietary Phosphate.- 7.2. Influence of EHDP.- 7.3. Influence of l,25(OH)2D3.- 8. Mechanism of Tubular Adaptation.- 9. Tubular Adaptation and Disorders of the Renal Pi Transport.- 10. Conclusions.- 11. References.- 10 Role of Extracellular Fluid Volume Expansion and Diuretics in Renal Handling of Phosphate.- 1. Introduction.- 2. Volume Expansion and Phosphate Excretion in the Rat and the Dog.- 3. Volume Expansion and Phosphate Excretion in Humans.- 4. Mechanism of Phosphaturia during Volume Expansion.- 5. Effects of Diuretics on Phosphate Excretion.- 5.1. Osmotic Agents.- 5.2. Mercurial Diuretics.- 5.3. Carbonic Anhydrase Inhibitors.- 5.4. Potassium-Sparing Diuretics.- 6. References.- 11 Influence of Calcium on Renal Handling of Phosphate.- 1. Introduction.- 2. Physiologic Studies.- 2.1. Effect of Calcium Infusion on the Serum Inorganic Phosphate Concentration and Its Filtration Characteristics.- 2.2. Influence of Calcium on Renal Hemodynamics.- 2.3. Effect of Calcium Infusion on the Absorption of Phosphate by the Renal Tubule.- 2.4. Studies during Hypocalcemia.- 2.5. Summary of Physiologic Studies.- 3. Pathologic Studies.- 3.1. Introduction.- 3.2. Renal Glomerular Insufficiency.- 3.3. Primary Hyperparathyroidism.- 3.4. Vitamin-D-Resistant Rickets with Hypophosphatemia.- 3.5. Hypoparathyroidism.- 4. References.- 12 Renal Handling of Phosphate in Renal Failure.- 1. Introduction.- 2. Factors Affecting Renal Handling of Phosphate in Renal Failure.- 3. Role of Serum Phosphorus.- 4. Renal Handling of Phosphate after Renal Transplantation.- 5. References.- 13 Tubular Defects in Phosphate Reabsorption in Clinical Medicine.- 1. Introduction.- 2. Diseases Manifested by a Tubular Phosphate Leak.- 2.1. Primary Renal Tubular Phosphate Hyperexcretion.- 2.2. Secondary Renal Tubular Phosphate Hyperexcretion.- 2.3. Phosphate Loss as Part of a Complex Tubulopathy.- 3. Conditions Associated with Increased Renal Tubular Retention of Phosphate.- 3.1. Pseudohypoparathyroidism (PHP).- 3.2. Other Conditions of Phosphate Retention.- 4. References.