DR. PAVY AND DIABETES 31 



into the circulation, simultaneously with sugar, there is an 

 increase of what he termed the "amylose" carbohydrate of the 

 blood, a more complex substance than sugar itself. This pointed 

 to an influence upon synthetic rather than upon destructive or 

 oxidative changes. Now some confirmation of these results has 

 recently been obtained. When pancreatic tissue is ground up with 

 muscle tissue, better still, when an alcoholic extract of boiled 

 pancreas is mixed with muscle plasm and dextrose is added, the 

 sugar disappears from the mixture with considerable rapidity. 1 

 The disappearance either does not occur or occurs much more 

 slowly, when the dextrose is in contact either with muscle alone 

 or with pancreas alone. What has been actually observed in 

 such experiments is a diminution in reducing power and this 

 has always been interpreted as meaning that the sugar under- 

 goes destruction. But it has been shown quite lately that, as a 

 matter of fact, the disappearance of the dextrose is due to its 

 condensation into a more complex sugar having a smaller reduc- 

 ing power. 2 Here then, we find, at least in a limited sense, 

 a confirmation of Pavy's contentions ; for if experiments such as 

 those described really bear upon the physiological happenings 

 in the body, a synthesis of some sort would seem to precede the 

 utilisation of sugar by the tissues. 3 



Further inquiries into this point will lead us to consider 

 the more purely chemical side of the whole question and 

 that very small modicum of knowledge concerning it which 

 can be discussed in terms of molecular structure. 



It must not be forgotten that though dextrose or grape sugar 

 is by far the most prominent physiological sugar, the animal 



1 Otto Cohnheim, Zeitsch. xliii. 401 (1904); ib. xlvii. 253(1906). Also Hall, 

 Amer. Journ. of Physiol, xviii. 283 (1907). 



2 Levene and Meyer, Journ. Biol. Chem. ix. 97 (191 1). 



3 Since the above was written, Knowlton and Starling have published (Proc. 

 Roy. Soc. lxxxv. 218, 191 2) an account of experiments which demonstrate in a 

 striking manner the importance of the pancreatic function. The heart of an 

 animal made diabetic by removal of the pancreas is shown to leave unchanged 

 any sugar supplied to it by way of the circulation, while under similar experimental 

 conditions the heart of a normal animal uses the supply. When, however, a 

 pancreatic extract is added to the blood, the heart from the diabetic animal also 

 utilises the sugar. Such experiments show clearly that the pancreas influences 

 the processes of utilisation and is not concerned merely with the maintenance of 

 stability in carbohydrate deposits. They do not decide, however, whether oxida- 

 tion is directly accelerated or whether the pancreas promotes a process which 

 necessarily precedes oxidation. 



