352 DIABETES MELLITUS. 



[Leucin ( ? guanin), sarkin, xanthin, cystin, and tyrosin occur pathologically in 

 certain diseases where marked chemical decompositions occur.] 



4. The inorganic substances found in the human liver are potassium, 

 sodium, calcium, magnesium, iron, manganese, chlorine, and phosphoric, 

 sulphuric, carbonic, and silicic acids ; while copper, zinc, lead, mercury, 

 and arsenic, are accidentally deposited in the hepatic tissue. 



175, Diabetes Mellitus, or Glycosuria. 



The formation of large quantities of grape-sugar by the liver, and 

 its passage into the blood (p. 62), and from the blood into the urine, 

 are related to the above-mentioned normal conditions. Extirpation of 

 the liver in frogs (Moleschott), or destruction of the hepatic cells as 

 by fatty degeneration from poisoning with phosphorus or arsenic 

 (Salkowski) do not cause this condition. It occurs for several hours, 

 however, after the injury of a certain part the centre for the hepatic 

 vaso-motor nerves of the floor of the lower part of the fourth ventricle 

 (Cl. Bernard's piqure); also after section of the vaso-motor channels in 

 the spinal cord, from above down to the exit of the nerves for the 

 liver, viz., to the lumbar region, and in the frog to the fourth vertebra 

 (Schiff). When the vaso-rnotor nerves, which proceed from this centre 

 to the liver, are cut or paralysed in any part of their course, mellituria 

 or glycosuria is produced. All the nerve-channels do not run through 

 the spinal cord alone. A number of vaso-motor nerves leave the spinal 

 cord higher up, pass into the sympathetic, and thus reach the liver; so 

 that destruction of the superior (Pavy), as well as of the inferior 

 cervical sympathetic ganglion, and the first thoracic ganglion (Eckhard), 

 of the abdominal ganglia (Klebs, Munk), and often of the splanchnic 

 itself (Hensen, v. Graefe), produces diabetes. The paralysis of the 

 blood-vessels causes the liver to contain much blood, and the intra- 

 hepatic blood-stream is slowed. This disturbance of the circulation 

 causes a great accumulation of sugar in the liver, as the blood-ferment 

 has time to act upon the glycogen and transform it into sugar. By 

 stimulation of the sympathetic at the lowest cervical and first thoracic 

 ganglion, the hepatic vessels at the periphery of the liver lobules 

 become contracted and pale (Cyon, AladofF). It is remarkable that 

 glycosuria when present may be set aside by section of the splanchnic 

 nerves. This is explained by supposing that the enormous dilatation 

 and congestion, or the hyperaemia, of the abdominal blood-vessels 

 thereby produced, renders the liver anaemic. 



A number of poisons which paralyse the hepatic vaso-motor nerves produce 

 diabetes in a similar way curara (when artificial respiration is not maintained), 

 chloroform, ether, chloral, amyl nitrite, carbon disulphide, morphia, mercuric 



