250 ON THE EXCRETION OF 



offered of the close physiological relationship between the 

 animal and vegetable products, despite minor differences in 

 chemical structure.* 



Phlorhizin experiments. In confirmation of the view that 

 kynurenic acid excretion is incidental to excessive proteid 

 katabolism, additional experiments on annuals suffering from 

 phlorhizin diabetes are presented. It has been shown that 

 under these conditions sugar production goes on in the fasting 

 animal directly at the expense of tissue proteid, the amount of 

 nitrogen in the urine going parallel with the amount of sugar 

 excreted ; f and the sugar excretion may thus go on even in 

 the absence of glycogen in the liver. : Lusk and his co- 

 workers have shown that in the fasting dog a constant ratio 

 of dextrose to nitrogen excreted is maintained during phlo- 

 rhizin diabetes (D: N: : 3.75: 1), and that feeding meat or 

 gelatin does not change the ratio. The figures indicate a pro- 

 duction of about 60 grams of dextrose from 100 grams of pro- 

 teid, and it has furthermore been found that in this form of 

 diabetes the proteid metabolism may increase to an extent as 

 high as 560 per cent above that in simple inanition. Tables 

 J and K show the extent of kynurenic acid production observed 

 on two fasting dogs during phlorhizin diabetes. The phlo- 

 rhizin, dissolved in dilute sodium carbonate solution, was intro- 

 duced subcutaneously about every eight hours. Water was 

 given ad libitum. 



Here again the production of kynurenic acid during fasting 

 is observed. Coincident with the appearance of the sugar in 

 the urine occurs a rise in nitrogen excretion accompanied like- 

 wise by an increase in kynurenic acid. The figures become 

 more striking when the daily averages of the period preceding 

 and succeeding the phlorhizin days are presented in contrast. 



* Of. Rutgers, Zeitschrift fUr Biologic, 1888, xxiv, p. 861. 



t Cf. for example, Cremer u. Bitter, Zeitachrift fur Biologic, 1893, xxix, 

 p. 256. 



t Thiel, Arch. f. exper. Pathol. and Pharmakol, 1887, xxiu, p. 142. Cf . also 

 Hedon, Comptes rendus de la Soc. de Biologic, Paris, 1897, (10), iv, p. 60. 



Reilly, Nolan, and Lusk, Amer. Journ. Physiol., 1898, i, p. 396. 



