Originally published in ArMv for Kemi 26 A, 4 (1948). 



69. TURNOVER OF RIBOSENUCLEIC ACID IN THE 

 JENSEN-SARCOMA OF THE RAT 



H. EuLER, G. Hevesy and W. Solodkowska 

 From the Institute for Research in Organic Chemistry, Stockholm 



In previous papers the rate of formation of labelled desoxyribosenucleic 

 acid in the Jensen-sarcoma in rats upon the administration of labelled 

 phosphate was investigated. 



In the present paper the results of investigations into the rate of 

 renewal of the ribosenucleic acid in the Jensen-sarcoma of the rat will 

 be reported. 



EXPERIMENTAL 



A few microcuries of labelled phosphate of negligible weight dissolved 

 in 0.1 ml physiological sodium chloride solution were subcutaneously 

 injected into rats (weighing 125— 165 gm) inoculated with Jensen-sarcoma. 

 Two hours after the injection the rats were sacrificed. The blood plasma 

 and the sarcoma were secured and the inorganic phosphate was extrac- 

 ted with a 7 percent CCI3COOH solution from both the plasma and an 

 aliquot of the sarcoma tissue. The specific activity of the nucleic acid 

 was determined on the greatest part of the sarcoma tissue, a minor part 

 being applied in the determination of the specific activity of the in- 

 organic P. The first mentioned determinations were made by the method 

 described by Schmidt and Thanhauser^i). This method is based on the 

 assumption that after thorough extraction with trichloracetic acid and 

 ether, alcohol, chloroform and methanol the nucleic acids are the only 

 phosphorus compounds present in the tissue. If the tissue purified in 

 this way is dissolved in IN NaOH solution at 37°, the desoxyribose- 

 nucleic acid remains unchanged, while the ribosenucleic acid is split into 

 mononucleotides<2). From the alcaline solution, CCI3OOH precipitates 

 desoxyribosenucleic acid and the ribosenucleotides are present in the 

 filtrate. Then the desoxyribose and the ribose fractions were ashed and 



^i^G. Schmidt and S. J. Thanhauser, J. Biol. Chem. 161, 83 (1945). 

 ^2^ G. Schmidt, R. Arbiles, B. H. Swartz and S. J. Thanhauser, J. Biol. 

 Chem. 170, 760 (1947). 



