I in METABOLISM OP THE C \KK«>m DRAT] - 



* 



disturbances involving various of the ductli ands, particularly the 



pancreas, the adrenals, the parathyroids and the pituitary. The influ- 

 ence of certain of these glands may be closely bound up with thai 

 exercised through the nervous control, as we have seen to be the c 

 with the adrenal gland. Whether it is by the production of hormo 

 directly necessary for proper carbohydrate metabolism, or by I 

 moval fit »m the blood of Buch substances as interfere with this p 

 that the ductless glands functionate, is one of the main problems 

 have i" consider. 



Utilization of Glucose in Tissues. Although the experimental diab< 

 induced by disturbances in the function of the ductless glands is dependent 

 in ilic first instance on an upset of the glj oogenic function and later on glu- 

 coneogenesis, the utilization of glucose in the tissues ultimately 1" 

 interfered with. It is therefore important thai we should dig »r a 



momenl to consider briefly whal is known regarding ilic process by 



which sugar becomes utilized in the organism. Tlmt glucose 1 mes 



used it]) by active muscle there can be no doubt. Thus, if the muscles 

 of one leg in the frog are tetanized, the glycogen content, compared with 

 thai of the other leg, will be found to be diminished. 



At first sight it mighl appear thai the easiest way to study the utiliza- 

 tion of glucose in the muscles would be to compare its concentrations 

 in the Mood flowing to and coming from the muscle. The muscle that 

 has been most successfully employed in studies of this kind has been the 

 heart. Some years ago Starling and Knowlton" examined the consump- 

 tion of sugar by the excised mammalian heart, and in their earlier 

 experiments seemed to be aide to show that the extent to which this 

 consumption occurred was I milligrams per gram heart muscle per 

 hour. A more thorough repetition of tli^s, ■ experiments later by Pat- 

 terson and Starling 28 showed, however, that the results can furnish no 



criterion of the actual consumption of glucose by the tissue ,,.j a unt 



of the fad that the tissue itself may store away large quantil - 

 carbohydrate in an unused state i.e., as glycogen. 



Other in\ estimators have thought to study the utilization of glue 



by observing the pate at which it disappears from drawn blood kept i'i 



a Sterile condition at bodj temperature for some hours after death. 



This process is failed glycolysis, and it has been assumed that the : 



iinilar to that which occurs in the tissues themselves an assumpl 

 however, for which there is no warranty. Indeed, it may readily be 

 shown that the glycolysis occurring in blood has very little if anything 

 to do with the utilization of sugar in the tissues, for it has b und 



that glucose disappears from drawn blood very slowly indeed when 



