516 DISEASES OF THE INSULAR APPARATUS OF THE PANCREAS 



shown that a similar sugar center lies also further centrally, in the subtha- 

 lamic region. In sugar puncture the stimulus travels over the paths of the 

 sympathetic, and leads to an unburdening of liver glycogen and to hypergly- 

 cemia. If the conduction is interrupted in the spinal cord above the giving- 

 off of the splanchnics, or if the liver is previously rendered sugar-free, as for 

 instance, by strychnine, the puncture is of no avail. Until up to a few years 

 ago this is as far as the mechanism of sugar puncture had been explained, 

 nor did we know how the impulse was carried over from the splanchnics to 

 the liver. The investigations of the last few years have shown that the chro- 

 maffin tissue is to be regarded as the governing device. Already Blum had 

 expressed the opinion that sugar puncture acted by way of the suprarenals. 

 In common with Eppinger and Rudinger, I showed that in thyroidless dogs 

 adrenalin glycosuria as well as " sugar puncture" glycosuria were not induced. 

 Both were therefore prevented by the same factor. Waterman and Smith 

 found after puncture a mydriatic substance in the serum. But to-day we 

 must consider the methods used by these authors for the demonstration of 

 adrenalin as insufficient. A further analogy between adrenalin glycosuria 

 and sugar puncture lies in the appreciable hyperemia of the liver that occurs 

 after each procedure, as Priestly and / have pointed out. After each pro- 

 cedure there occurs an increase in blood-pressure (E. Neubauer) . For the con- 

 vincing experiment we have to thank R. H. Kahn. He showed that after 

 sugar puncture the staining of the suprarenals to chrome dyes as well as the 

 pressor power of the suprarenal extract decreases. If the puncture is done 

 after previous section of both splanchnics the glycosuria remains absent, 

 as is known, and the staining of the suprarenals to chrome dyes is retained. 

 It was shown therewith, in confirmation of the experiments of Nishi, that 

 the left splanchnic supplies both suprarenals, while the right splanchnic gives 

 off fibers only to the right suprarenal; for on action of the right splanchnic 

 the puncture makes both suprarenals poorer in adrenalin, while on section 

 of the left splanchnic only the right suprarenal suffers somewhat in its adrena- 

 lin contents. Electrical stimulation of the splanchnic (section of the nerves 

 and stimulation of the peripheral stump) elicits glycosuria. Tschebokraroff 

 had previously shown that the adrenalin contents of the blood of the supra- 

 renal veins is increased by electrical stimulation of the splanchnics. 



Therefore the action of sugar puncture may be explained by an afferent 

 impulse conducted along the splanchnics, which leads to an unloading of the 

 chromaffln. How adrenalin occasions a dissemination of the sugar from the 

 liver is not as yet clear. E\ Neubauer thought that the hyperemia of the 

 liver was alone the cause of the dissemination of glycogen. I think, however, 

 that against this speaks the fact that there are agents that bring about dis- 

 tinct hyperemia of the liver without producing glycosuria. Such an action 

 has pituitrinum infundibulare, for instance. The hyperemia of the liver 

 may, however, very well favor the development of a glycosuric action, as has 



