KYNURENIC ACID. 253 



this drug in the case of a dog. The 10-kilo animal had been 

 fed three days on a diet consisting of albumin, 15 grams ; car- 

 bohydrate, 50 grams ; fat, 40 grams ; under which conditions 

 nothing more than traces of kynurenic acid were found in the 

 urine. On the fourth day the animal received three subcu- 

 taneous injections of amyl nitrite (about 6 c.c. being given hi 

 all). By the following day the dog was dead. The urine 

 (128 c.c.) removed from the bladder contained no kynurenic 

 acid; 4.69 grams sugar were present, and the ratio of dextrose 

 to nitrogen was found as 7.4 : 1. Traces of albumin were also 

 found, in agreement with observations of Araki.* The high 

 ratio of dextrose to nitrogen indicates that the sugar found 

 could not have its origin wholly in proteid decomposition, nor 

 was this to be expected under these conditions (previous feed- 

 ing, etc.). But Thielf has shown that amyl nitrite fails to 

 produce characteristic glycosuria in hens, although phlorhizin 

 is effective in these animals. Amyl nitrite diabetes is there- 

 fore doubtless of a distinctly different type from that produced 

 by phlorhizin ; at any rate the absence of kynurenic acid in 

 the urine in our single experiment corresponds with the slight 

 evidence of proteid katabolism obtained. 



Experiments on other animals. So far as we are aware, no 

 one has succeeded in finding kynurenic acid in the urine of 

 any animal other than the dog. Hofmeister4 after careful 

 examination, failed to find it in human urine. It has likewise 

 been found missing hi the urine of the rabbit, wolf, || andfox.|| 

 We have searched for kynurenic acid in the urine of the cat 

 during inanition as well as during meat and milk diet, but 

 always with negative results. In view of the evidence of our 



* Araki, Zeitschr. f. physiol. Chemie, 1891, xv, p. 553. The older literature 

 is referred to here. 



t Thiel, Arch. f. exper. Pathol. u. Pharmakol., 1887, xxiii, p. 142. 



t Hofmeister, Zeitschr. f. physiol. Chemie, 1881, v, p. 69. Eckhard, long 

 before, had missed it in human urine ; see Ann. Chem. Pharm., 1856, xcvii, 

 p. 358. 



Schmidt, Ueber das Verhalten einiger Chinolinderivate im Thierkorper, 

 mit Riicksicht auf die Bildung yon Kynurensaure. Inaugural-Dissertation, 

 Konigsberg, 1884. 



II Capaldi, Zeitschr. f . physiol. Chemie, 1897, xxiii, p. 87. 



