DDT ANTAGONISM TO DIELDRIN STORAGE IN ADIPOSE TISSUE OF RATS.

Storage of dieldrin in the adipose tissue of female rats was markedly depressed when DDT and dieldrin were fed simultaneously. The amount of dieldrin present in the tissues of rats fed 1 and 10 parts of dieldrin per million was significantly reduced by the addition of 5 ppm DDT to the feed. The addition of 50 ppm DDT to the feed caused a 15-fold reduction in the amount of dieldrin stored in rats fed 1 ppm dieldrin, and a 6-fold reduction in rats fed 10 ppm dieldrin. This antagonistic effect of DDT suggests that the criteria used in predicting the pharmacological effects of combined residues of related insecticides need some revision.