Rat liver microsomes are shown to contain an enzyme system
which converts the cyclodiene insecticides, aldrin, heptachlor and
isodrin to their corresponding epoxides, dieldrin, heptachlor epoxide,
and endrin. The microsomal fraction of 450 milligrams of liver from
male rats epoxidates 80 percent of a 20 to 50 microgram aldrin substrate...