186 INTERMEDIATE METABOLISM 



known to occur both in man and in lower animals when 

 they are in a state of emotional excitement. Concerning 

 this neurogenic form of glycosuria two points must be 

 noted. First, that it is only transient; secondly, that it 

 does not occur when the liver has been previously depleted 

 of its store of glycogen. The fault therefore hes solely in 

 an excessive discharge of glucose from the hver. 



Before discussing further the manner in which the 

 excessive production of glucose is brought about it is 

 necessary to mention that glycosuria can be caused by 

 injection of adrenalin. This comphcates the problem con- 

 siderably, for we have to decide whether the diabetes is 

 due directly to the stimulation of the hepatic cells through 

 the splanchnic nerve or indirectly to the coincident 

 stimulation of the suprarenal glands. 



Experiments on this point have led to conflicting results. 

 By some observers it has been found that after removal 

 of the suprarenals stimulation of the splanclmics fails to 

 cause glycosuria ; by others this has been denied. If, the 

 suprarenals being intact, the hepatic branches of the 

 splanclmics be cut and their peripheral ends stimulated 

 glycosuria occurs, while the same experiment performed 

 some time after excision of the glands causes only slight 

 glycosuria. These experiments indicate that sympathetic 

 excitation of the liver when the blood contains its normal 

 amount of adrenahn is adequate to provoke the conversion 

 of glycogen into glucose. When the splanchnics are stimu- 

 lated after division of their hepatic branches only a slight 

 degree of glycosuria occurs. We must therefore conclude 

 that in this form of glycosuria two factors interplay — the 

 direct action of the nerves upon the hepatic cells and the 

 coincident stimulation of the suprarenal glands. 



Pancreatic Diabetes 



When the whole or nearly the whole of the pancreas is 

 removed there follows a profound diabetic condition which 



