222 



On the Nature of Pancreatic Diabetes. 



In the reverse experiment a normal heart was fed with diabetic blood. 

 In this case the consumption of sugar during the first hour was only slightly 

 below normal and steadily diminished during the succeeding two hours, as is 

 shown by the following figures : — 



1st hour. 2nd hour. 3rd hour. 



3-5 2-5 1-7 



The obvious interpretation of these two sets of experiments is that the 

 tissues and blood normally contain some substance, the presence of which 

 is essential for the direct utilisation of sugar by the tissues. This substance 

 is gradually used up in the tissues, and therefore has to be continually 

 replaced from the blood if the utilisation of sugar is to continue. 



IV. Is this Substance derived from the Pancreas ? 

 To answer this question an extract of pancreas was made by grinding up 

 the gland, boiling it in slightly acid Ringer's solution, and filtering it to free 

 it from the coagulated proteins ; 10 c.c. of the filtrate were neutralised 

 with a few drops of sodium carbonate solution and added to the blood 

 circulating through the heart of a diabetic animal. The addition was in each 

 case made during the second hour of the experiment, in order that the con- 

 sumption of sugar by the heart during the first hour might be tested. The 

 following results were obtained : — 



Diabetic Heart Fed with Diabetic Blood. 

 Consumption of Sugar in milligrammes per grm. of Heart Muscle. 



1st hour 2nd hour 



(blood alone). (after addition of pancreatic extract). 



1-5 . > 1 4-3 



0-5 3-0 

 0-5 28 

 0-5 36 



It will be seen that in every case the addition of a boiled extract of 

 pancreas, whether derived from the same animal (dog) or from another 

 animal (cat), raised the sugar consumption by the heart from a figure which 

 was within the limits of experimental error to a point closely approaching 

 that found in normal hearts. The effect of the pancreatic extract in 

 improving the action of the heart was evident during the experiment itself. 

 In most cases the heart in the diabetic animal, under the conditions of the 

 experiment, has a lower rate of beat than that found in the normal animal. 

 The effect of adding the extract of pancreas was to quicken the rate of beat 

 up to a normal figure. Thus, in one experiment, the rate of beat during the 



