R ADIAT rON-TNDUCED DISTUR P> ANCES OF T H E 

 LIPIDS OF CELLULAR MICR08TRUCTURES 



N. N. DOEMIN AND V. D. BLOKHINA 



Parlor Ixstitate of Physiol ogij and Institute of BiopJiysics, U.iS.S.B. Aaideiinj 



of Sciences, Leningrad, U.S.S.R. 



SUMMARY 



The content of different lipid fractions has been determined in celhilar micro- 

 structures of the rabbit liver and intestinal mucosa under normal conditions and 

 after total exposure to 1,000 r y-rays of cobalt-60. Determinations were made on 

 summary joreparations of cytojalasmic organelles and of hyaloplasm of liver cells 

 24 and 72 hr after exposure and in mitochondria, microsomes and hyaloplasm of 

 intestinal mucosa cells 2, 24 and 72 hr after exposvire. Post-irradiation changes 

 were studied in the following lipid fractions: "free" — extractable by petrolevim 

 ether; "loosely-bound" — extractable by methanol -chloi'oform mixture (minus 

 the "free" lipids); and "firmly -bound" — which can be extracted after alkaline 

 hydrolysis from the residue after methanol-chloroform treatment. 



Considerable changes in the content of individual lipid fractions and their 

 quantitative interrelation in various micromorphological cellular components 

 may occur within 2 hr of radiation injury. Later on these changes proceeded 

 in various directions. The radiation-induced changes in the content of the various 

 lipid fractions of sub -cellular comj^onents of irradiated intestinal mucosa differ 

 from those of liver. The simultaneous changes of the lipid fractions of microsomes, 

 mitochondria and hyaloplasm may be variously directed. 



The changes in the composition of li]:)id complexes of cellular organelles pro- 

 duced by ionizing radiation may be a cause of many subsec£uent disturbances 

 in the cellular metabolism of damaged tissues. 



Recent advances in cytology enable ns to visnalize clearly the great 

 role of individual cellular micro- and ultramicrostructiu*es in the bio- 

 logical activity of cells. The present-day achievements of biochemistry 

 have made available many concrete facts characterizing the partici- 

 pation of cell micromorphological components in the metabolic pro- 

 cesses and their regulation. The biochemical turnover in cells proceeds 

 in a complex multiphase organized system, and its individual links are 

 localized and intimately connected with definite structures. It may be 

 assumed that these structures composed of biochemically active sub- 

 stances are not merely ^^assive plastic formations, but represent 

 spatially oriented participants of many-sided reactions which "endow"' 

 them with high-rate arrangement. Heterogeneity of the cell contents 



141 



