[Reprinted from the Journal of Physiology. 

 Vol. XXXIV. Nos, 1 efc 2, March 13, 1906.] 



ON THE ALLEGED ADAPTATION OF THE PANCREAS 

 TO LACTOSE. BY R. H. ADERS PLIMMER, D.Sc. 



(From the Physiological Laboratory, University College.) 



IT has been shown by E. Fischer and W. Niebel (1) and by Portier (2) 

 that the pancreas of animals such as the dog, ox, horse, calf, and pig } 

 contains no ferment capable of hydrolysing lactose. This result was 

 confirmed for adult animals in 1899 by Weinland (3) , who, however, 

 asserted that the presence or absence of lactase in the pancreas depended 

 on the previous diet of the animal. He found that lactase was a 

 constant constituent of extracts of pancreas made from sucking animals, 

 and that the effect of feeding dogs for some weeks with milk was to 

 cause the appearance of this ferment in the pancreas. This observation 

 of Weinland's was confirmed by Bainbridge (4) . Bainbridge extended 

 his observations also to the pancreatic juice, and found that here too the 

 administration of lactose to adult animals caused the secretion of lactase 

 in the juice. Bainbridge carried out an elaborate series of experiments 

 with the view of determining the exact mechanism by means of which 

 the adaptation of the pancreas to the presence of lactose in the alimen- 

 tary canal was effected, and concluded that the administration of lactose 

 caused the formation of some substance in the epithelial cells of the 

 intestine which was absorbed by the blood and carried to the pancreas, 

 where it gave rise to the formation of lactase. The effect of secretin on 

 such a pancreas was to cause the turning out of all the ferments which 

 it contained, including the lactase. 



Recently, however, Bierry (5) , in the course of a research on the 

 distribution of lactase, has examined extracts of the pancreas and the 

 pancreatic juice, in adult dogs fed on biscuit or meat, as well as in 

 other dogs which had been fed on lactose. He states that under 

 no circumstances can the lactose-splitting ferment be found either in the 

 pancreas or in the pancreatic juice, and ascribes the results of previous 

 observers to the insufficiency of the methods of analysis employed by 

 them. 



