rv 



NUCLEIC ACIDS AND NU C LE O P ROTEINS 



903 



TABLE 6 



DEOXYRIBOSIDE CONTENT OF ANIMAL TISSUES 



(Schneider, 1955) 



BRA^Y 





^ Expressed as thymidine. 



2 Animals decapitated without anesthesia. 



3 Hepatoma 37-bearing animals. 



^ Animals frozen in liquid air. 



^ Removed 2 min. after death of animal 



^ Hepatoma-bearing animals 



in the purine and pyrimidine composition of the DNA isolated from tumors. 

 However, the normal range of values was usually encompassed by the tumor 

 values. 



{ii) Nucleotides and nucleosides. The free deoxyriboside content of several normal 

 and neoplastic tissues were determined by microbiological assay (Schneider, 1955) 

 Table 6. 



It may be noted that the mouse tumors contained more deoxyribosides than the 

 normal tissues. All normal rat tissues were also higher than the corresponding 

 mouse tissues. The hepatoma was no higher than the liver or other rat tissues in 

 deoxyribosides. Schneider ascertained that most of the deoxy components meas- 

 ured were pyrimidine deoxyribosides, and that these compounds were localized 

 in the soluble fraction of the tissues. Of interest was the discovery in rat liver of 

 deoxyuridine which may be a precursor of thymidine. Further observations in 



Literature p. gig 



