1903.] Adaptation of the Pancreas to different Food-stuffs. 35 



" On the Adaptation of the Pancreas to different Food-stuffs." 

 Preliminary Communication. By F. A. BAINBRIDGE, M.B., 

 M.RC.P. Communicated by Professor E. H. STARLING, F.RS. 

 Received May 25, Read May 28, 1903. 



(From the Physiological Laboratory, University College, London.) 



It has been found by Walther and other observers that the chemical 

 composition of pancreatic juice varies in response to the stimulus of 

 different food-stuffs ; a fatty diet, for example, led to the secretion of 

 a larger amount of steapsin in the pancreatic juice than did a diet 

 devoid of fat. 



Further, Weinland showed that whereas the pancreatic juice of 

 adult dogs normally contained no lactase, the juice of dogs fed for 

 some days on milk contained lactase in large amount. 



My experiments have been made in the hope of determining, firstly, 

 whether the pancreas does adapt itself to different food-stuffs, and 

 secondly, by what means this adaptation takes place. 



Method. Milk was chosen as a convenient food, which could readily 

 be added to or excluded from the diet ; and the enzyme studied was 

 lactase, which converts lactose into galactose and dextrose. Dogs were 

 fed on milk, sometimes with the addition of pure lactose, for periods 

 varying from 12 60 days. Then the animals were anaesthetised with 

 morphia and A.C.E. mixture, and the pancreatic juice obtained by 

 means of secretin. 



A certain quantity of pure lactose was weighed, and made up to a 

 known volume. Part of this was estimated at once by Pavy's method ; 

 to another part pancreatic juice was added, and the mixture incubated 

 at 37 for 18 48 hours, chloroform or toluol being also added to 

 prevent bacterial action ; a control experiment was also made. 



The solution was then acidified with acetic acid, boiled for 

 several minutes, filtered, made up to a known volume, and estimated 

 by Pavy's method. In each experiment the same solution of Pavy's 

 fluid was employed for estimating the pure lactose, and the solution 

 after incubation, so as to exclude any error due to varying strengths 

 of the Pavy's solution ; moreover, the conditions as regards the duration 

 of the boiling of the sugar solutions during estimation, the rate at 

 which the Pavy's fluid was added, and other details were kept as far as 

 possible constant in every experiment. With these precautions, Pavy's 

 method was found to be extremely accurate, and it has the advantage 

 that the reducing power of inverted lactose is very much larger than 

 that of pure lactose. Almost invariably 50 c.c. Pavy's solution were 

 titrated at each observation, and the sugar solutions used for the 

 estimation had a concentration of about 0'5 per cent. 



D 2 



