DIGESTION AND ABSORPTION OF PROTEIN 7 



acids being liberated. Fischer and Abderhalden (i 26) and Abderhalden, 

 London and Voegtlin (43) showed later in a long series of experiments 

 that a large number of the polypeptides were resistant to the action of 

 the gastric juice, although they were rapidly broken down by the pan- 

 creatic juice (for further details see Dr. Plimmer's monograph in this 

 series, Part II, pp. 43-46). Oppenheimer and Aron again (309) found 

 that serum, which is normally resistant to the action of trypsin, could 

 be digested by this enzyme if it had been previously subjected to the 

 action of pepsin. 



Gastric Absorption. 



As regards the question as to whether absorption takes place in 

 the stomach or not, there has been much discussion. London and his 

 school deny that absorption ever takes place, whereas Tobler (398) 

 states that after a protein meal he has observed the disappearance of 

 from 22 to 30 per cent, of this material from the stomach. Salaskin 

 (348) believes that Tobler is right in his contention that absorption of 

 protein can and does take place in the stomach, but he does not bring 

 forward any convincing evidence or experiment in support of his be- 

 lief. If this absorption be as great as Tobler makes out, it is ex- 

 traordinary that it has escaped the observation of so many of the 

 competent workers in this field. Abderhalden, Prym and London 

 (44) have for example shown that even if amino acids be given per os 

 they leave the stomach practically completely through the pylorus, 

 absorption first taking place in the duodenum. 



The present general conclusion would seem to be that if any ab- 

 sorption of protein digestion products take place from the stomach, 

 under normal conditions, it must be a small one. 



