Effect of DDT on induction of microsomal enzymes and deposition of calcium in the domestic chicken.

These results show that PB pretreatment induced microsomal enzyme activity in all stages studied (as measured directly or by decreased sedation time), induction of microsomal enzymes by DDT was inconsistent in the enzyme assays and pretreatment with DDT and its analogs increased sedation time of PB inin vivo tests, an apparent inhibition of microsomal enzymes. Dieldrin and insecticides of a similar mode of action were found to decrease the sedation time of PB in young chicks, but dieldrin did not alter the sedation time of PB in mature birds. Addition of DDT-DDE to the food of laying hens had no effect on eggshell calcium. These experiments lend additional support to the hypothesis that alteration of oxidative enzyme activity and/or calcium deposition by chlorinated hydrocarbons does not appear to be a general phenomenon among the class Aves.