C in bone, however, was significantly reduced (P<0.05) in fish exposed to 

 toxaphene for 90 days, and was low in all fish, including the controls, at 

 150 days. This response in the controls was probably due to the chronic 

 effects of the diet itself. After 90 days exposure, backbone collagen was 

 significantly reduced (P<0.05) only in the highest concentration; at 150 

 days, however, it was significantly reduced in all toxaphene treated fish. 

 Thus, when fish are exposed to an organochlorine contaminant such as toxa- 

 phene, the increased use of vitamin C by the liver in hydroxylative detoxi- 

 cation mechanisms may reduce the amount in the bones by as much as 50 per- 

 cent. This reduction of vitamin C in bone is believed to inhibit the 

 formation of hydroxyproline from proline and reduces collagen formation. 



CONCLUSIONS 



Biochemical characteristics such as hydroxyproline and collagen concen- 

 trations in bone can be used as indicators, and within limits, predictors 

 of growth in fish thereby shortening chronic toxicity tests. Although 

 growth can be directly related to collagen and hydroxyproline metabolism 

 in fish, the mechanism by which growth is reduced is not known. Other 

 biochemical processes requiring vitamin C could also be affected when 

 large amounts of the vitamin are used by the liver in detoxication of 

 organic contaminants through microsomal hydroxylative enzymes. 



ACKNOWLEDGEMENT 



This research was sponsored in part by the U.S. Environmental Pro- 

 tection Agency through Contract No. EPA-IAG-01 53(D) and EPA-IAG-141 (D) 



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