1 6 GENERAL PART 



Further, a specific influencing of the metabolic processes, for example in an 

 athyrosis, is to be thought of; further, a modeling influence on the skeleton 

 through alteration of the muscle tonus, etc., etc. It would, however, be 

 a mistake to bring into relationship with the ductless glandular system 

 all variations and diminutions or increases in the growth energy of the 

 protoplasm. 



Influence of the Ductless Glands on the Regulation of Metabolism. 



The ductless glands assume a still more considerable influence in the regu- 

 lation of metabolism. I shall here choose only a few of the most marked 

 examples. First let us consider the carbohydrate metabolism. The pan- 

 creatic insular apparatus governs the carbohydrate assimilation, for after 

 extirpation of the pancreas the glycogen formation in the liver and also 

 otherwise in the tissues, especially the muscles, is markedly disturbed. That, 

 this consists chiefly in a disturbance of glycogenesis seems to arise from the 

 fact that on low-grade insufficiency of the pancreas the disturbances first 

 become manifest only on alimentary overloading, while otherwise the regu- 

 lation of the carbohydrate metabolism is proceeding normally. Then an 

 increased sugar production occurs first in the high grades of the disturbance, 

 for now there occurs also on fasting hence, with full exclusion of the ali- 

 mentary influence hyperglycemia and glycosuria. 



On the other hand, the mobilization of glycogen seems to stand chiefly 

 under the influence of the chromafiin tissue, for artificially induced hyper- 

 adrenalinemia (through subcutaneous injection of adrenalin or through 

 sugar puncture) brings about a rapid melting down of the glycogen present 

 in the liver and muscles, and perhaps also an increased combustion of sugar 

 (for after injection of adrenalin we saw a rise of the respiratory quotient). 

 Thereby occurs hyperglycemia and eventually glycosuria; after extirpation 

 of the suprarenals or in Addison's disease there exists, on the contrary, 

 a hypoglycemia. 



Both the pancreatic insular apparatus and the chromaffin tissue are to be 

 regarded as most important regulators of the carbohydrate metabolism, 

 and we must add to them as a regulator the thyroid gland; for, as previously 

 mentioned, in typical myxedema the assimilation limits are raised, and in 

 Basedow's disease or in artificial thyroidism they are not rarely reduced, in 

 some cases to such an extent that spontaneous glycosuria occurs. As I here 

 again emphasize, the thyroid gland seems to influence especially the pan- 

 creatic insular apparatus or the hormone produced by it, as here the ali- 

 mentary factor is so prominent. A similar regulatory influence, although 

 probably not such a strong one, seems to proceed from the hypophysis; I 

 shall speak of this in the appropriate chapter. 



So far as the protein metabolism is concerned, we have known for some 



