314 DIABETES MELLITUS. 



pass through the communicating branches into the splanchnic nerves. According 

 to the opinions of earlier investigators, all of the paths, however, do not pass 

 through the spinal cord alone. A number of vasomotor fibers for the liver leave 

 the spinal cord at a higher level, and pass further on in the course of the sym- 

 pathetic nerve to the liver. Thus, destruction of the uppermost, as well as of the 

 lowest, cervical ganglion, and of the first dorsal ganglion, of the abdominal ganglia, 

 often also of the splanchnic nerves, is followed by glycosuria. The paralyzed, 

 dilated vessels render the liver exceedingly vascular, and the blood-stream in them 

 is slowed. This disturbance of the circulation gives rise to the presence of a large 

 amount of sugar in the liver, as the blood-ferment has time to effect transformation 

 of the glycogen. Irritation of the sympathetic nerve at the last cervical and first 

 dorsal ganglia causes contraction of the hepatic vessels at the periphery of the 

 acini, with anemia. It is a remarkable fact that glycosuria when present can 

 be removed by division of the splanchnic nerves. This is explained by the cir- 

 cumstance that the enormous hyperemia of the intestines occurring after this 

 operation renders the liver anemic. 



Also a number of poisons that paralyze the vasomotor nerves of the liver 

 cause diabetes in the same manner, namely curare, when artificial respiration 

 is not maintained; carbon monoxid, amyl nitrite, orthonitrophenyl-propionic 

 acid and methyldelphinin ; less constantly morphin, chloral hydrate "and others. 

 The toxic products of some of the infectious diseases also act in the same way 

 at times. Blood-stasis of other sort in the liver also appears capable of caus- 

 ing glycosuria, as, for example, after mechanical stimulation of the liver. In 

 this category probably belongs the glycosuria following the injection of dilute 

 saline solutions into he blood, as a result of which the changes in the shape 

 of the red corpuscles cause stasis. Also the fact that repeated venesection 

 makes the blood richer in sugar may, perhaps, be explained by the slowing of the 

 circulation. 



Persistent irritation of peripheral nerves may also be active through a reflex 

 influence upon the center for the vasomotor nerves of the liver. The appearance 

 of sugar in the urine has sometimes been observed as a result of irritation of the 

 central stump of the pneumogastric nerve, likewise after irritation of the central 

 stump of the depressor nerve. Even division and central irritation of the sciatic 

 nerve may cattse the appearance of sugar from the urine ; in this way is explained 

 the occurrence of glycosuria in cases of sciatica and other nervous disorders. 



According to Schiff, stagnation of the blood in various extensive portions 

 of the body is said to increase the development of the ferment in the blood to 

 such a degree that diabetes results. Qf this character must be considered the 

 glycosuria that occurs after compression of the aorta or the portal vein, although 

 the pressure exerted under such circumstances may, perhaps, paralyze nerve- 

 paths concerned. According to Eckhard, injury to the vermis of the cerebellum, 

 in the rabbit, is said to bring about diabetes. In human beings, also, affections 

 of the nervous structures mentioned may cause diabetes. 



Various explanations have been assigned in elucidation of the ultimate cause 

 of these symptoms: 



(a) The glycogen of the liver may without interference be converted into sugar, 

 as ferment may be conveyed to the liver-cells from the blood-mass, in consequence 

 of its stagnation. Therefore the normally functionating vasomotor system of the 

 liver, and especially its center, is, in a certain sense, to be designated an inhibitory 

 system controlling the production of sugar. 



(6) If it be assumed that, under normal conditions, a certain, even though 

 small, amount of sugar flows continually from the liver into the blood, through the 

 hepatic veins, diabetes might be explained as depending on the abolition of those 

 metabolic processes (deranged combustion of sugar) that constantly remove this 

 sugar from the blood under normal conditions. 



The following experiments appear to confirm this latter view: Independently 

 of one another, v. Mering and Minkowski, as well as de Dominicis, observed that 

 dogs become diabetic after total removal of the pancreas. According to Min- 

 kowski, it is the function of the pancreas to consume the sugar of the blood. Lepine 

 and Barral state that a ferment is produced in the pancreas that destroys the 

 sugar in the blood; so that after extirpation of the pancreas, sugar must accord- 

 ingly accumulate in the blood. The ferment is contained in abundance within 

 the leukocytes in the portal vein; some is derived from the lymph, perhaps also 

 from other abdominal glands. After extirpation of the pancreas, the blood con- 

 tains little sugar-destroying ferment. Kolisch and von Stejskal found much 

 jecorin. 



