SECRETION OF THE DUCTLESS GLANDS. 887 



which he perfused the heart and pancreas, singly and together, 

 with a Ringer sohition containing dextrose, the perfusion being 

 carried out under aseptic conditions. When the pancreas alone 

 was perfused the dextrose suffered a change in optical rota- 

 tion without any alteration in reducing power. When the heart 

 and pancreas were perfused together or in sequence the dex- 

 trose suffered a diminution in both optical rotation and reduc- 

 ing power. Since both of these properties were restored in part 

 toward normal on subsequent hydrolysis of the perfused hquid 

 it would seem that the dextrose had undergone a condensa- 

 tion to some form of polysaccharid. The author suggests that 

 the pancreas furnishes some substance, presumably an enzyme, 

 which causes a preliminary change in the dextrose of an unknown 

 nature, but probably a condensation. When this material is 

 brought to the heart or other tissues there is a further change to a 

 form of carbohydrate which is especially adapted for utilization. 

 This action of the pancreas seems to be limited to dextrose; 

 levulose, at least, is not affected in a similar way. Other investi- 

 gators adopt an entirely different view of the relation of the pancreas 

 to carbohydrate metabolism. They believe that the internal secre- 

 tion of the pancreas regulates in some way the output of sugar 

 from the hver. In the absence of this secretion the liver gives off its 

 glycogen as sugar too rapidly, the sugar contents of the blood are 

 thereby increased (hyperglycemia) above normal, and the excess 

 passes out in the urine. The large amount of work that has been 

 done upon pancreatic diabetes, as well as diabetes mellitus in man, 

 seems to favor the general view that in these conditions the dif- 

 ficulty Hes not in the processes of glycogenesis or glycogenolysis, 

 but in the consumption of sugar by the tissues. In pancreatic 

 diabetes certainly the balance of evidence supports the theory of 

 an internal secretion on the part of the pancreas, which plays an 

 essential role in the normal process of sugar consumption in the 

 tissues. One very striking bit of evidence in this direction is 

 furnished by Carlson* and his co-workers. They find that if 

 extu-pation of the pancreas is effected in a pregnant dog near term, 

 the animal does not exhibit glycosuria until the pups are born or 

 are removed by cesarean section. The internal secretion from the 

 fetal pancreas suffices to protect the mother. Experimental work 

 on dogs has shown that the various characteristics of chnical 

 diabetes in man may be reproduced m dogs by partial depan- 

 creatization. When the pancreatic deficiency is sufficient to 



* Carlson and Drennan, "American Journal of Physiology," 28, 391, 1911; 

 also 36, 217, 280, 1915, and "Journal of Biological Chemistry," 13, 465. 



