Originally published in Ark. Kem. 21A, No. 6 (1945). 



77. FORMATION OF NUCLEIC ACID IN SARCOMA SLICES 



Lucie Ahlstrom, Hans Euler and George Hevesy 



From the Institute for Research in Organic Chemistry, Stockholm 



The numerous types of molecules which occur in the organs have a 

 limited life-time. They decompose and are newly synthesized in the course 

 of the metabolic processes taking place in the organs. Their concentra- 

 tion is the result of synthetic and degradation processes. The application 

 of isotopic tracers makes it possible to break up the resultant into its 

 components. The newly formed molecules are of course labelled when 

 tracers are present. Knowing the total number of molecules present, 

 from chemical analysis, and knowing the number of molecules formed, 

 as shown by the isotopic tracer, the number of molecules degraded and 

 therefore information regarding the two components concerned in the 

 resultant process can be obtained. 



In the isolated organs many of the types molecules occurring in them 

 disappear but, of course, at different rates. It has not previously been 

 decided whether the decay of phosphatides, nucleic acid and other mole- 

 cules in the organs, after these organs have been isolated, is a purely 

 unilateral process or the result of a slow synthetic and a more rapid 

 degradative process. The use of an isotopic tracer, however, permits 

 the detection of a synthetic process, even if it takes place at a very low 

 rate, and thus also the discovery of whether the process is strictly unila- 

 teral or not. Chaikoff and his collaborators^^^ found that radioactive 

 phosphatide molecules are formed in tissue sections of liver, kidneys 

 and intestinal mucosa which have been immersed in a radioactively 

 labelled phosphate solution, and a similar result was obtained by Bul- 

 LiARD, Grundland and MdussA^^^ with sections of the suprarenal 

 capsule. 



Fries, Schachner and Chaikoff^^^ later detected the formation of 

 radioactively labelled phosphatides in Nervus Sciaticus and in cerebral 



1 A. Robinson, I. Peblmann, S. Ruben and I. L. Chaikoff, Nature 141» 

 119 (1938). 



2 H. BuiLLAUD, I. Grundland and A. MoussA, C. R. Acad. Set., Paris 207, 

 745 (1938); Ibid. 208, 843 (1939). 



