82 LECTURE V. 



shown to be different from the other forms by the investigations under 

 the leadership of Minkowski, carried out by Andreas Thiel 1 and by von 

 Mering. 2 These investigators have shown that geese with extirpated 

 livers eliminate sugar after the injection of phloridzin, whereas we have 

 seen that with the other forms of glucosuria it is essentially the liver alone 

 which takes part in the sugar-formation. 



Much more important than the results of these last experiments 3 is the 

 above-mentioned fact that most investigators have failed to find any 

 evidence of glucohemia in the case of phloridzin-glucosuria. The con- 

 clusion has, therefore, been drawn that the elimination of sugar after 

 phloridzin poisoning is due to the abnormal permeability of the kidney 

 epithelium for sugar. Thus the sugar in the blood would become less and 

 less, and indirectly the liver, and perhaps the other places where glycogen 

 is stored, would be compelled to give up sugar. To support the assump- 

 tion, that the glucosuria produced by phloridzin is of a renal nature, N. 

 Zuntz 4 has published a proof, which is not, however, conclusive. He 

 injected, by means of a trocar, a solution of phloridzin through the walls 

 of the renal artery into the blood-stream. The kidney to which the glu- 

 coside was carried directly was the first to eliminate sugar. Pfliiger 5 

 believes that it is not impossible that the first separation of sugar may be 

 due to a decomposition of the phloridzin itself. At present we cannot be 

 sure as to what is the correct explanation of phloridzin glucosuria. Only 

 this is known, the matter is by no means so simple as has been 

 assumed. 6 Above all, it must be mentioned that starving animals will 

 also eliminate sugar after the introduction of phloridzin, and repeated 

 additions of the glucoside result in renewed glucosuria, 7 and to such a 

 degree that the question as to whether food other than carbohydrates can 

 give rise to the sugar formation now presents itself. 



Our knowledge concerning the formation of sugar in the animal organism 

 was considerably increased by the discovery of von Mering and Minkowski 8 

 in the year 1889 that dogs always suffered from severe glucosuria after 

 complete extirpation of the pancreas. If a small part of the pancreas is left 



1 Inaug. Dissert. Konigsberg, 1887. 



2 Loc. cit. Z. klin. Med. 14, 415 (1888). Cf. Minkowski and Thiel: Arch. exp. 

 Path. Pharm. 23, 142 (1887). 



8 For a critical discussion see E. Pfliiger: Das Glykogen und seine Beziehungen zur 

 Zuckerkrankheit (1905). 



4 Arch. Anat. Physiol. 1895, 570. 

 6 Loc. cit. p. 539. 



6 Cf. Carl Jakobj: Arch, exper. Path. Pharm. 36, 213 (1895). 



7 Cf. Lusk: Z. Biol. 42, 31 (1901). O. Loewi: Arch, exper. Path. Pharm. 47, 48 

 (1902). 



8 Ibid. 26, 371 (1890). O. Minkowski: Untersuchungen iiber den Diabetes mellitus, 

 Leipzig, 1893. 



