CARBOHYDRATES. 87 



lie in the assumption that the pancreatic gland produces a substance which 

 either directly or indirectly influences the metabolism of carbohydrates. 

 It is altogether out of the question to imagine that the sugar in the blood 

 undergoes any change by passing through the gland. The regulation of 

 the carbohydrate metabolism must take place indirectly, i.e., the tissue of 

 the pancreas influences in some way or other the organs whose task it is 

 to build up or to consume the sugar. This assumption has gradually 

 gained ground, especially after the experimental explanation of Lepine 

 concerning pancreatic-glucosuria had been found untenable. Lepine, 1 as 

 has been mentioned, discovered the presence of a ferment in the blood 

 which was able to decompose sugar. This glucolytic ferment was assumed 

 to be produced by the pancreatic gland. The ferment was supposed to pass 

 continually through the thoracic duct into the blood and circulate in this 

 attached to the white corpuscles. Lepine found that in animals deprived 

 of the pancreas there was a considerable diminution of the amount of this 

 ferment, or, in other words, the power of the blood to consume sugar 

 was considerably diminished. Thus the assumption was made that pan- 

 creatic-glucosuria was a result of the fact that the ferment was not formed 

 after the pancreas was removed. Lepine's views, however, were soon 

 contradicted, and to-day the hypothesis may be said to be completely 

 shattered. De Dominicis, 2 for one, showed that in animals suffering from 

 pancreatic-glucosuria there was no diminution in the elimination of sugar 

 when blood from the portal vein of normal animals, which according to 

 Lepine would be rich in the ferment, was injected into them. On the 

 contrary, the result was that the glucosuria became more severe. Arthus 3 

 found that the blood contained in ligated vessels was not capable of 

 decomposing sugar, and therefore contained no glucolytic ferment. More- 

 over, from many sides it has been shown that glucolysis appears as a post- 

 mortem phenomenon, and that it has any connection with the metabolism 

 of carbohydrates in the living organism has been flatly denied. In fact, the 

 whole theory of glucolysis in the blood rests upon an extremely slight 

 foundation, and a great deal may be said against it. Lepine in his experi- 

 ment failed entirely to take into consideration many phenomena which 

 appear after extirpation of the pancreas, such as, for example, the fact that 

 after the operation the liver loses its glycogen. In this connection, 

 Marcuse's 4 observation is interesting that glucosuria in frogs, resulting 

 from extirpation of the liver, disappeared if at the same time the pancreas 

 was removed. 



In the last lecture, we found that the muscles are the chief consumers 



1 Compt. rend. 113, 729 (1891); *Wtf. 113, 1014 (1891). 



2 Wiener med. Wochschr. 42-45 (1898). 



3 Arch. Physiol. 1891, 425; 1892, 337. 



4 Z. klin. Med. 26, 225 (1894). Cf. A. Montuori: Arch. ital. biol. 25 (1896). 



