124 THE AMINO ACIDS 



is nearly equal to the sum of the two individual influ- 

 ences. This indicates a distinct difference between the 

 cause of the specific dynamic action of glucose and 

 that of alanine. Two types of processes are here sug- 

 gested, namely, a metabolism of plethora and amino 

 acid stimulation. Carbohydrate or fat metabolites 

 which are being absorbed from the intestine into the 

 blood bring about a metabolism of plethora. In the 

 metabolism of plethora the influx of carbohydrate or 

 fat enables the cells to oxidize at a higher level through 

 the increased mass action of food particles which are 

 available. (Lusk.) A recent attempt by Lusk to ex- 

 plain "amino acid stimulation" of the cells has resulted 

 in the conclusion that some at least of the amino acids 

 even when they are not oxidized "yield products of 

 metabolism, either hydroxy or ketone acids which act 

 as stimuli to induce higher oxidation in the organism. 

 This is the conclusive proof of a true chemical stimu- 

 lation of protoplasm within the mammalian organism. 

 It explains the specific dynamic action of protein." 



As has been shown repeatedly throughout this book 

 the effects characteristically produced by protein are 

 gradually being ascribed as a function of the amino 

 acids. The amino acids therefore may be regarded 

 not alone as pabulum for the restoration of depleted 

 cells but must also be looked upon as playing a distinct 

 and significant role in the rate or extent of cellular 

 metabolism. 



