CONTENTS 



CHAPTER PAGE 



I. INTRODUCTION TO THE STUDY OP METABOLISM. PROTEIN DIGESTION 



IN THE STOMACH 1 



Introduction. Protein Digestion in the Stomach. "Mock Meal" 

 and Pawlow's Ventriculus. Nervous Mechanism of Secretion. 

 Action of Psychic Influences. Excito-secretory Stimuli. Gastric 

 Secretin. Inhibition of Secretion. Origin of Free Hydrochloric 

 Acid in Gastric Mucous Membrane. Physico-chemical Explana- 

 tions. Acid-production by Marine Snails. Determination of 

 Acidity of Gastric Juice. Binding of Hydrochloric Acid by Proteins. 

 Extent of Protein Digestion in the Stomach. Comparative Physio- 

 logical Considerations. Efforts to Isolate Pepsin. Methods of 

 Pepsin Determination. Law of Pepsin Fermentation. Propepsin. 

 Pseudopepsin. Passage of Pepsin into Intestine. Resistance of 

 Stomach to Autodigestion . Origin of Round Ulcer of the Stomach. 

 Chymosin. Ultramicroscopic Studies of Lab-process. Association 

 of Bacteria in Lab-process. Plastins. Question of the Identity 

 of Pepsin and Rennin. 



II. THE PROTEOLYTIC PANCREATIC FERMENT 33 



Transfer of Food from Stomach into the Intestine. Passage of 

 Intestinal Contents into the Stomach. Pancreatic Fistulas. 

 Secretin. Secretin and Cholin and the Vasodilatins. Entero- 

 kinase. Activation of Trypsinogen by Calcium Salts, etc. Indi- 

 viduality of Trypsin. Conversion of Trypsin into Zymoid. 

 Action of Trypsin on Polypeptids. Adaptation of the Pancreatic 

 Secretion to the Food. Quantitative Determination and Ferment 

 Law of Trypsin. Toxicity of Parenterally Introduced Trypsin. 



III. PROTEIN-DIGESTION IN THE INTESTINE 50 



Erepsin. Extent of Protein Dissociation in the Intestine. Passage 

 of True Proteins and High-Molecular Protein-Derivatives into 

 the Blood. Resorption of Iodized Proteins. Objections to the 

 Resorption of Albumoses and Aminoacids. Residual Nitrogen. 

 Synthesis of Digestive Products. Parenteral Introduction of 

 Protein. Protein Synthesis from Advanced Cleavage of Protein. 

 Abderhalden's Experiments. Application of these Results in 

 Sickroom Dietary. Relation of Amides in Metabolism in Vege- 

 tarians. Protein Synthesis from Ammonium Salts. London's 

 Studies. Summary. 



IV. PROTEOLYTIC AND PEPTOLYTIC TISSUE FERMENTS 75 



Autolysis a Complex Process. Antiseptic Difficulties in Autolysis 

 Experiments. Is Autolysis the Continuation of an Intravital 

 Process? Deamidizing Tissue Ferments. Importance of Auto- 

 lysis in Various Pathological Processes. Autolysis and the Re- 

 gressive Changes in the Living Body. Relation to Bacterial Proc- 

 esses. Proteolytic Ferments of Leucocytic Origin. Effect of Ex- 

 trinsic Factors upon Autolysis. Abderhalden's Investigations 

 upon Proteolytic Tissue Ferments. Detection of Proteolytic 

 Tissue Ferments by Means of Glycyltyrosin, Silk-peptone, and 

 Glycyltryptophane. Optical Method. Inhibition of Proteolytic 

 Processes by the Products of Protein Cleavage. Classification of 

 Proteolytic Ferments. Peptolytic Power of Blood Serum. 



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