150 N. N. DOBMIN AND V. D. BLOKHINA 



fractions f)f the cell organelles in the small intestinal mucosal cells 

 weie observed rather earlv, i.e. within 2 hr after irradiation. 



Undoubtedly, the early and subsequently noted divergence from the 

 norm in the lipid complexes of the cell organelles (both in content and 

 composition) which develop after the irradiation may in turn bring 

 about many alterations in cell metabolism. The oxidative transforma- 

 tions with the transport of electrons along the respiratory chain, oxida- 

 tive phosphorylation, peptide bond synthesis etc. associated with the 

 activity of mitochondria and microsomes should be stressed first of all. 



The results obtained raise a series of questions in the field. A deeper 

 knowledge of the pathological significance of these changes will require 

 a knowledge of the chemical composition of the lipid fractions examined 

 in our experiments. The quantitative and qualitative alterations in the 

 lipids of lipoprotein complexes especially deserve examination. It is 

 important to hnd \\'ays to solve the most intricate problems dealing 

 with the mechanism responsible for these disturbances and their issue 

 for the biochemical, and the entire biological activity of the cells. 



In fact, all these data lead to one common pro])lem of important 

 practical significance ; which of these alterations are a true consequence 

 of the destructive effect of ionizing radiation and which of them should 

 be ascribed to compensatory reactions on the part of the organism. 



REFERENCES 



Blokhixa, V. D. (li)59a). Med. Radiol. 4, No. 2, 37. 



Blokhina, V. D. (19o9b). Med. Radiol. 4, No. 1, 53. 



Blokhixa. V. D.. and Doemix, N. N., (19.J9). Biochliuia. 24, 723. 



Bloor, W. R. (1947). J. biol. Ghem. 170, 671. 



FoLCH, J., AscoLi, I.. Lees. M., Meath, J. A., and Le Barox, F. N. (19.")1). ./. bioL 

 Chem. 191, 833. 



Kuzix, A. M. (1955). Ses.sion of the U.S.S.R. Academy of Sciences on the Peaceful Uses 

 of Atomic Energy, July, p. 69. Department of Biological Sciences, Mo.scow; see also 

 Kuzix, A. M. and Strazhevskaia, N. B. (1957). "Racliobiologhia, Biologhicheskoie 

 deistvie izlucheniy", p. 50. Moscow. 



Ilyixa, L. I., Blokhixa. V. D., and Uspexskaia. M. S. (1957). Med. Radiol. 2, No. 4, 23. 



RoMAXTSEV, Ye F. (1952). "Deistvie rentgenovykh luchey na obmen lipidov (Xeitral- 

 nyie zhyry, fosfolipidy, zhirnyie kisloty)", Dissertation, Moscow. 



SissAKiAX, N. M. (1955). Reiaorts of the Soviet Delegation to 1st Int. conference on Peace- 

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 Moscow. 



DISCUSSION 



BACQ : You compare liver and the mucosa of the small intestine, but the conditions 

 found in these organs following radiation exposure are very different. Liver cells 

 are not destroyed, whereas cells of the intestinal mucosa undergo rapid degenera- 

 tion. Cell population changes also differ greatly in these organs. In the case of the 

 intestinal mucosa, within 24 lir of exposure you are dealing already with a cjuite 

 different cell population. 



Both in hver and in intestinal mucosa you have observed after exposure an 

 increase of the total lipids, as may be seen from the data you have presented. 



