144 



N. N. DOEMIN AND V. D. BLOKHINA 



extracted according to Folch and of the fatty acids released by snl)se- 

 qnent alkali hydrolysis (the fraction of the "firndy bound'" lipids). 



The (juantity of the "loosely bomid' li})ids was ascertained by esti- 

 mating the difference between the cinantity of li]>ids extracted with the 

 niethanol-chloroform mixture and that soliil)le in petroleum ether 

 ("free" lipids). 



The hyaloplasm comprises about 40 per cent of the total dry weight 

 of the liver cell cytoplasm. The a])proximate data with regard to the 

 content of the lipid fractions in the cytoplasmatic microstructures (in 

 round figures) were calculated on the basis of this value and the results 

 of the determination of li])id fractions in the entire cytoplasm and in 

 the hyaloplasm separately. 



The determinations were performed on control animals and at 24 

 and 72 hr following radiation injury; under the conditions of our 

 experiments these times corresponded to the beginning and the highest 

 point of the radiation disease. 



Under normal conditions the liver tissue in i*abbits is relativelv very 

 rich in lipids ; the total content of the latter in the cytoplasmic organ- 

 elles and in the hyaloplasm is approximately equal and comprises about 

 30 per cent of the dry weight. It was established that under normal 

 conditions according to the ratio between the separate lipid fractions 

 the cytoplasmic organelles and the hyalo]3lasm of the liver cells differ 

 greatly. In the cytoplasmic organelles all the lipids are actually in a 



Hours after irradiation 



Fig. 1. — The content (percentage of dry weight) of various li])id fractions in the cyto- 

 plasmic organelles of the rabbit liver cell imder conditions of acute radiation disease. 



I. Total lipid content ; 

 II. "Loosely bound" lipids; 



III. "Firmly bound" lipids 



IV. "Free" lipids. 



