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ADVENTURES IN RADIOISOTOPE RESEARCH 



Table 3 



Activity of 1 mgm desoxyribosenucleic acid P of growing Jensen sarcomata in percentage 

 of the activity of 1 mgm inorganic P from the 



<i) H. EULBE, and G. Hevesy, Kgl. Danske Vidensk. Selskab, Bid. Medd. of 7, 8 (1942). 

 <-> H. EULER, and G. Hevesy, Sv. Vet.-Akad. Arkiv /. Kemi, A 17, No. 30 (1944). 

 •'' Average of 4 not previously published results. 



sarcoma, while the desoxyribosenucleic acid concentration in the sarcoma 

 remains practically unchanged. We found the mean unpurified desoxy- 

 ribosenucleic acid content of 1 gm growing sarcoma to be 9.2 mgm, this 

 value representing the average of a very great number of investigated 

 Jensen sarcomata. For the spontaneously retrograde sarcoma the 

 corresponding figure was found to be 8.8 and for benzpyrene produced 

 sarcoma (cf. p. 738) the value was 8.0 



In the growing sarcoma an increase of the total desoxyribosenucleic 

 acid content by 1 per cent during the experiment leads to a formation 

 of labelled molecules up to at least 1 per cent of the desoxyribosenucleic 

 acid content of the sarcoma. Such an increase is thus clearly indicated by 

 the radioactive method. A decrease of the desoxyribosenucleic acid 

 content by 1 per cent, however, will hardly be indicated by tracer 

 experiments, since, to a very large extent, non-labelled molecules dis- 

 appear. Should we find a decreased percentage new formation of des- 

 oxyribosenucleic acid in the retrograde sarcoma, this result would thus 

 indicate that the mechanism of desoxyribosenucleic formation does not 

 function normally in the retrograde sarcoma. As seen above, this is not 

 the case; or the case only to a very restricted extent. 



This result illustrates the fact that the tissue autolysis, followed by 

 resorption, (the necrotic process) has very little in common with the 

 more subtile enzyme "new formation" process; a result which is in no 

 way surprising. Taurog and his associates(i) placed surviving liver slices 

 for a few hours in a Ringer solution containing labelled phosphate. An 

 appreciable part of the ^^p added was found to be present at the end of 

 the experiment in the phosphatides isolated in the tissue slices. A quanti- 

 tative determination of the extent of renewal of the tissue phosphatide 

 was not carried out, but it can be estimated to have amounted to a few 

 per cent. Simultaneously the decrease in the total phosphatide content 

 of the tissue slices was determined. It was found to be as much as 20 



^1^ A. Taurog, J. L. Chaikoff and J. Perlman, J. Biol.Chem. 145, 281 (1942). 



