360 



GEORGE BOSWORTH BROWN AND PAUL M. ROLL 



TABLE III 

 Incorporations of Various Precursors into the DNA of Intestine and Liver 



(Rat)" 



" Contractions used are explained in Table II, footnote a. 



* Time interval following administration. Two figures represent the duration of the administration and 

 the time interval following last injection. 

 ' Mucosa only. 



and Table IV, line 10 and footnote h). However, the only common basis yet 

 available for comparisons of the phosphate data with other precursors is 

 provided by the values relative to a single reference, since the results from 

 each of the other compounds studied are compared to a single reference 

 value (usually the activity of the administered compound). 



Many subsequent studies with P^^ or with adenine and formate have 

 shown differences of the same order of magnitude in the relative incorpora- 

 tions into the DNA's of the majority of these several organs (Table II), 

 with the renewals in intestine greater than those in spleen. However, in one 

 case, that of strain A mice, the incorporation of phosphorus was repeat- 

 g(jly96,ioo found to be greater in spleen than in intestinal DNA (Table II, 

 column 5), but in parallel experiments the incorporations of adenine, gly- 

 cine, and formate were greater in the intestine than in the spleen.^"" Ad- 

 ditional evidence on the relative incorporations into intestine and liver, 

 including data for ammonia and glycine, are summarized in Table III. 

 Although there may appear to be certain differences between the various 



** E. Hammarsten and G. Hevesy, Acta. Physiol. Scand. 11, 335 (1946). 



9« L. S. Kelly, A. H. Payne, M. R. White, and H. B. Jones, Cancer Research 11, 694 



(1951). 

 " E. E. Osgood, J. G. Li, H. Tivey, M. L. Duerst, and A. J. Seaman, Science 114, 



95 (1951). 

 88 A. Bendich, Exptl. Cell. Research. 3, Suppl. 2, 181 (1952). 



S9 A. Bendich, P. J. Russel, Jr., and G. B. Brown, J. Biol. Chem. 203, 305 (1953). 

 '<"> A. H. Payne, L. S. Kelly, and H. B. Jones, Cancer Research 12, 666 (1952). 

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