Mammalian Protein Metabolism

List of Contributors

Preface

Chapter 1 Historical Introduction: The Origin and Growth of our Present Concepts of Protein Metabolism

I. Discovery of Nitrogen and Its Biological Consequences: The Age of Black, Rutherford, and Lavoisier

II. Recognition of the Importance of Nitrogenous Compounds: The Nutritional Studies of Francois Magendie

III. Identification of the Proteins as a Chemical Class: The Theories of Liebig and Mulder

IV. The Development of Nitrogen Balance as a Technique for the Study of Protein Metabolism: The Era of Carl Voit

V. The Nutritional Studies of Voit and His Successors

VI. Studies on the Metabolism of Nitrogenous Materials since the Time of Voit

VII. Conclusion

References

Part I Biochemical Aspects of Protein Metabolism

An Introduction to Biochemical Aspects of Protein Metabolism

Text

Chapter 2 Protein Digestion and Absorption in Nonruminants

I. Introduction

II. Digestion in the Stomach

III. Digestion in the Intestine

IV. The Endogenous Protein

V. Absorption

References

Chapter 3 The Digestion and Absorption of Nitrogenous Compounds in the Ruminant

I. Introduction

II. Endogenous Nitrogen Entering the Reticulum and Rumen

III. Utilization of Nitrogenous Compounds in the Rumen

IV. Passage of Nitrogenous Compounds from the Rumen

V. The Nitrogen Cycle within the Body of the Ruminant

References

Chapter 4 Free Amino Acids and Peptides in Tissues

I. Introduction

II. Where Do Amino Acids Go when They Disappear from the Circulation?

III. General Biological Significance of Cellular Uptake of Amino Acids

IV. Influence of the Uptake Process on the Direction of Amino Acid Metabolism

V. Mode of Amino Acid Transport

VI. Peptides in Tissues

VII. Intravenous Amino Acid Nutrition: An Intensified Form of the General Problem of Supplying Amino Acids to Cells

VIII. Homeostasis of the Plasma Amino Acid Levels

References

Chapter 5 The Metabolic Fate of Amino Acids

I. Pathways of Amino Acid Degradation

II. Synthesis of Urea

III. Formation of Nitrogenous Cell Constituents from Amino Acids

IV. Urinary Excretion of Amino Acids

V. Biosynthesis of Nonessential Amino Acids in the Mammalian Body

VI. Gluconeogenesis from Amino Acids

VII. Nutritional Adaptation of Amino Acid Metabolism

VIII. The Cause of the Specific Dynamic Action of Proteins

References

Chapter 6 Protein Biosynthesis in Mammalian Tissues

Part I. The Mechanism of Protein Synthesis

I. The Problem of Protein Biosynthesis

II. Major Events Leading to a Hypothesis of Protein Synthesis

III. Amino Acid Activating Enzymes

IV. Soluble Ribonucleic Acid

V. Ribosomes

VI. Ribosomes and Protein Synthesis

VII. Genetic Control of Protein Synthesis: Synthesis of Templates

VIII. Protein Synthesis in Mitochondria

IX. Protein Synthesis in Isolated Nuclei

X. Conclusion

References

Chapter 7 Protein Biosynthesis in Mammalian Tissues

Part II. Studies on Turnover in the Whole Animal

I. Introduction

II. Different Types of Protein Turnover

III. General Problems Arising in the Interpretation of Turnover Data

IV. Protein Turnover in Specific Systems

V. Attempts at Assessment of Over-all Rate of Protein Synthesis in the Whole Mammal

VI. Concluding Remarks

References

Chapter 8 Metabolism of Plasma Proteins

I. Introduction

II. Distribution of Proteins between Plasma and Lymph

III. Sites of Catabolism and Replacement

IV. Interpretation of Plasma Radioactivities

V. Interpretation of Total Body I131 Radioactivities

VI. Absolute Measurement of Protein Synthesis Rate

VII. Role of the Liver in Plasma Protein Metabolism

VIII. Possible Sites of Catabolism

IX. Rates of Plasma Protein Catabolism

X. Rates of Plasma Protein Synthesis

XI. Plasma Protein Metabolism in Dietary Deprivation

XII. Qualifications to a First-Order Kinetic Concept

XIII. Possible Significance of Turnover

XIV. Appendix on Preparation of Labeled Proteins

References

Chapter 9 Some Aspects of Hormone and Protein Metabolic Interrelationships

I. Introduction

II. Hormones and Fetal Growth

III. Hormones and Prepubertal Growth

IV. Hormones, Body Growth, and Nitrogen Balance

V. Hormones and Serum Proteins

VI. Hormones and Protein Metabolism in Tissues and Organs

VII. Pregnancy

VIII. Protein Nutrition and Hormone Action

IX. Steroids in Recovery from Protein Depletion

X. Hypophysectomy and Protein Repletion

References

Chapter 10 General Aspects of the Regulation of Protein Metabolism by Diet and Hormones

I. Introduction

II. Tissue Response to Dietary Protein Intake, with Reference to Labile or Reserve Body Protein

III. Influence of Dietary Carbohydrate and Fat on Protein Metabolism

IV. Hormonal Action and Body Protein Distribution

V. Interaction of Diet and Hormones in the Regulation of Protein Metabolism

VI. General Conclusions and Summary

References

Chapter 11 Elimination of Nitrogen from the Body

Introduction

I. Excretion of Nitrogenous Compounds in the Urine

II. Dermal Losses

III. Fecal Excretion

IV. The Concept of Nitrogen Balance

References

Author Index

Subject Index