THE INTERNAL SECRETION OF THE PANCREAS 429 



disturbance somewhere in the functional chain, that is to say, in 

 either the central nervous system, the pancreas, or the liver. 



A similar view was expressed by Thiroloix and, more re- 

 cently, by Pfliiger. These authors assume that the sugar con- 

 tents of the blood are dependent upon two opposing factors, both 

 of which are under the control of the central nervous system. 

 Of these two factors, one is the mechanism by which sugar is 

 formed in the liver, which is governed by the centre in the 

 medulla oblongata. The other factor, antagonistic to the first, 

 is supplied by the so-called anti-diabetic activity, which limits 

 the production of sugar ; it is situated in the pancreas and is also 

 under the control of the nervous system. Thiroloix assumes that 

 the inhibitory action of the pancreas is performed by the agency 

 of an internal secretion which is regulated by the nervous sys- 

 tem ; Pfluger, on the other hand, believes that its anti-diabetic 

 property is supplied to the pancreas by nerves which originate 

 in the duodenum. This view is supported by Herlitzka. But 

 Pfluger concedes that the glandular substance of the pancreas may 

 play a part in Sandmayer's diabetes; he suggests that the 

 epithelial cells may possibly supply an anti-diabetic ferment to 

 the blood-stream. 



It is evident from these theories concerning the nature of 

 pancreatic diabetes, that the conception of the pancreatic function 

 as an inhibition of the formation of sugar, lies at the root of all 

 the later teaching. Further information concerning the field of 

 activity of the pancreatic hormone, hence a new point of view 

 in regard to pancreatic diabetes, has recently been supplied by 

 the discovery of the relationship between the metabolism of the 

 carbohydrates and the activity of the other internal secretory 



organs. 



Particularly important was the discovery and analysis of 

 adrenalin glycosuria, for it showed the enormous influence of the 

 suprarenal, or rather of the adrenal system, upon the sugar 

 economy of the organism. Further, we know that adrenalin, by 

 mobilizing the reserve glycogen and thus promoting the forma- 

 tion of sugar from other material, raises the sugar contents of 

 the blood. The antagonism between the activity of adrenalin 

 and that of the pancreatic hormone is chiefly symptomatic in its 

 expression. The action of adrenalin is modified in certain direc- 

 tions by the internal secretion of the pancreas. In Zuelzer's 

 experiments, the effect of pancreatic extract in inhibiting adrenalin 

 glycosuria might be explained by the assumption that the excess 

 of sugar in the blood undergoes combustion by the agency of 

 the pancreatic hormone introduced into the economy. Zuelzer's 

 results permit, however, of another explanation. It may be that 

 the antagonistic effect of the two substances is the outcome of 

 their antagonistic influence upon the same physiological site; in 

 other words, the activity of an apparatus may be inhibited by 



