Fish Physiology: Nitrogen Excretion (eBook)

Front Cover 1
CONTENTS 6
Contributors 10
Preface 12
Chapter 1. Evolutionary Considerations of Nitrogen Metabolism and Excretion 14
I. Introduction: The Changing Roles of Ammonia and Urea 14
II. Evolution of Urea as an Osmolyte and Excretory Product in Fish 18
III. Uricotely and Other End Products 35
IV. Summary and Epilogue 37
References 39
Chapter 2. Protein Synthesis 44
I. Introduction 44
II. General Models of Protein Synthesis 45
III. Protein Synthesis and Amino Acid Flux 50
IV. Factors That Modify Protein Synthesis 70
V. Energetic Cost of Protein Synthesis in Fish 80
VI. Summary 80
References 82
Chapter 3. Amino Acid Metabolism 90
I. Introduction 90
II. Digestion and Uptake of Amino Acids 92
III. Delivery Systems 92
IV. Tissues 96
V. Exercise 104
VI. Hormonal Regulation 104
VII. Diurnal Rhythms in Amino Acid Metabolism 106
VIII. Diet and Starvation 107
IX. Temperature 108
X. Salinity 109
XI. Anoxia 110
XII. Summary 111
References 112
Chapter 4. Ammonia Toxicity, Tolerance, and Excretion 122
I. Introduction 122
II. Ammonia Toxicity to Fish 123
III. Strategies to Reduce, Tolerate, or Avoid Ammonia Toxicity 136
IV. Summary 152
References 153
Chapter 5. Ontogeny of Nitrogen Metabolism and Excretion 162
I. Early Development of Fishes 162
II. Free Amino Acids 164
III. Nutritional Demands 177
IV. Nitrogen End Products and Their Chemistry in Solution 182
V. Nitrogen Metabolism 189
VI. Nitrogen Excretion 194
VII. Summary 198
References 199
Chapter 6. Influence of Feeding, Exercise, and Temperature on Nitrogen Metabolism and Excretion 214
I. Introduction 214
II. Feeding and Nitrogen Metabolism 215
III. Metabolic Fuel Usage and Nitrogen Metabolism 220
IV. Exercise and Nitrogen Metabolism 222
V. Temperature and Nitrogen Metabolism 229
VI. Other Nitrogen Products? 232
VII. Excretion Mechanisms 236
VIII. Elasmobranchs 238
IX. Concluding Remarks 241
References 242
Chapter 7. Urea and Glutamine Synthesis: Environmental Influences on Nitrogen Excretion 252
I. Introduction 252
II. Carbamoyl-Phosphate Synthetase III and Nitrogen Excretion in Fish 257
III. Glutamine Synthetase and Ammonia Detoxification 263
IV. Urea Cycle in Elasmobranchs 266
V. Urea Cycle in Teleosts: Adaptation to Unique Environmental Circumstances 269
VI. Summary 282
References 283
Chapter 8. Urea Transport 292
I. Introduction 292
II. Urea Transport in Mammalian Systems 294
III. Physiology of Urea Transport in Fish 302
IV. Prospects for Future Research and Evolutionary Perspectives 333
References 315
Chapter 9. Nitrogen Compounds as Osmolytes 322
I. Introduction 322
II. Types and Contents of Osmolytes 324
III. Metabolism and Regulation of Osmolytes 329
IV. Properties and Functions of Nitrogen Osmolytes 333
V. Mechanisms of Compatibility and Counteraction: Osmolytes and Water Structure 344
VI. Evolutionary Considerations 346
VII. Practical Applications, Exceptions, and Unanswered Questions 347
References 348
Index 356
Other Volumes in the Fish Physiology Series 370