Chromatographic analysis showed comparatively rapid (within hours) ac- 

 cumulation of DDT and its metabolites {o,p' - DDE, o,p' - DDD, o,p' - DDT, 

 p,p' - DDD and p,p' - DDT) in fish tissues. Estimation of the DDT residue 

 content at different phases of intoxication enabled an understanding of the 

 dynamics of this process during fish convulsions (Phase 1), and at adynamia, 

 preceding death (Phase 2). 



The quality of DDT and its metabolites increased in the tissues during 

 the processes of the development of intoxication, within a few hours. Total 

 DDT content in the muscles of silver carp increased from 0.103 ppm during 

 the first phase to 0.501 ppm at the second phase of intoxication. In liver 

 this increase was from 1.99 ppm during the first phase to 3.38 ppm during 

 the second phase. Similarly, in the intestine the range was from 2.83 ppm 

 at the first phase up to 0.79 ppm during the second phase. 



Accumulation of DDT and its metabolites in fish was also accompanied by 

 a phase change of a number of biochemical indices, the group B vitamins in 

 particular. For example, vitamin Bi content increased in carp liver by 

 131 percent when locomotor activity was increased (Phase 1), and decreased 

 by 14 percent at the time of adynamia (Phase 2) when compared with control 

 values. These data are indicative that vitamins are of considerable impor- 

 tance in the process of intoxication. 



During the first phase of intoxication, the vitamin B] content, which 

 is of considerable importance in metabolic processes, increases. During the 

 second phase when metabolism processes are disturbed, the organism's vital 

 resources are exhausted and the vitamin B] quantity is greatly reduced. 



Changes in the levels of nicotine-amide enzymes in the fish tissues were 

 also indicative of alterations in the oxidation-reduction processes. The 

 total quantity of oxidized and reduced forms of nicotine-amide enzymes de- 

 creased in fish liver as a result of the action of lethal quantities of DDT, 

 from 554 ppm in the control group to 307 ppm in test animals. Similarly, 

 the ratio of oxidized and reduced forms also decreased in the liver tissue 

 from 2.26 ppm in control fish to 0.96 ppm in test species. Since nicotine- 

 amide enzymes are of great importance in the regulation of cellular respira- 

 tion, the alterations observed were indicative of considerable metabolic 

 disturbances in fish tissues under the influence of DDT. 



Coupled with these observations was an extensive formation of metabo- 

 lites of DDT in organs and tissues rich in lipids. The formation of p,p' - 

 DDE; o,p' - DDT; p,p' - DDD; p,p' - DDT metabolites in intestine and inner 

 fat were of analogous character. DDT accumulation in fatty tissue during 

 the first phase of intoxication is accompanied by the formation of the 

 metabolite n,n' - DDD, while levels of o,p' - DDT and p,p' - DDE increase. 

 During the second phase this ratio changed to domination by p,p' - DDD and 

 o,p' - DDT. In the intestine, p,p' - DDT, and o,p' - DDT predominated 

 during the first phase, and by the second phase p,p' - DDD was dominant. In 

 the muscles of silver carp during the first phase of intoxication, p,p' - 

 DDT content was the greatest, while o,p' - DDT and p,p' - DDD were pro- 

 nounced in the second phase. 



114 



