14G PTEROYLGLUTAMIC ACID 



7. In contrast to the preceding report^^ concerning the ineffectiveness of 

 iron, the anemia was found to respond to iron and copper as well as to 

 uropterin. These results with xanthopterin were repeated by the same 

 authors^"* with other samples of xanthopterin. However, Koschara reported 

 that Rominger was unable to get any response with the same sample of 

 uropterin that Tschesche had used in his experiments.-^^ 



Xanthopterin was also found to have a hemapoietic effect when injected 

 into fingerling salmon with nutritional anemia. ^^ The anemia was produced 

 by feeding the salmon a high protein diet containing yeast as a source of 

 the vitamin B complex. The erythrocyte counts of the control fish varied 

 between 501,000 and 916,000 per cubic millimeter, whereas in those in- 

 jected with 50 7 of xanthopterin the counts varied between 944,000 and 

 1,305,000. In a subsequent study these same investigators^^ observed a 

 similar anemia on salmon raised on diets of 20 % liver and 80 % spawned-out 

 salmon. The ability of salmon to become anemic on a diet containing 20 % 

 liver certainly indicates that PGA is ineffective in this blood dyscrasia. A 

 larger variability existed in the erythrocyte count of these fish, but by 

 selection a group of uniform experimental fish having an average count of 

 800,000 cells per cubic millimeter was obtained. Injection of a single dose 

 of xanthopterin at a level of 10 mg. per kilogram of body weight increased 

 the RBC to 1 ,300,000 per cubic millimeter; 20 and 40 mg. per kilogram of 

 body weight increased it to approximately 1,580,000, with the peak on the 

 third to fifth day. The erythrocyte count returned to its original level 

 within 10 to 14 days. The erythrocyte counts of normal wild salmon caught 

 in fresh or salt water were in the range of 1,500,000 to 1,600,000. Compari- 

 son of different species of salmon raised on the experimental diet and having 

 the same initial erythrocyte count showed that different species varied in 

 their response to xanthopterin. 



Variable results have been reported with xanthopterin in sulfonamide-fed 

 rats. Totter and Day^^ observed that 20 7 of xanthopterin administered 

 daily to rats receiving 1 % sulfasuxidine produced an immediate weight 

 gain and increased the leucocytes to 9400 cells per cubic millimeter, com- 

 pared with 3420 for the controls. The growth rate and the white blood cells 

 were not completely restored to normal, which showed that the response 

 produced by xanthopterin was qualitatively different from that produced 

 by liver fractions. These results with xanthopterin have not been confirmed 



»4 R. Tschesche and H. J. Wolf, Z. physiol. Chem. 248, 34 (1937). 



35 W. Koschara and A. Hrubesch, Z. physiol. Chem. 258, 39 (1939). 



36 R. W. Simmons and E. R. Norris, J. Biol. Chem. 140, 679 (1941). 

 " E. R. Norris and R. W. Simmons, J. Biol. Chem. 158, 449 (1945). 

 38 J. R. Totter and P. L. Da.y, J. Biol. Chem. 147, 257 (1943). 



