Localization of [ 14 C]DDT in the ventral nerve cord of the cockroach, Periplaneta americana (L.)

[ 14 C]DDT was used as a probe to determine the subcellular localization of DDT in the ventral nerve cord (VNC) of the cockroach, Periplaneta americana (L.). Male cockroaches were injected intra‐abdominally with [ 14 C]DDT and their VNCs removed at 1 h post‐injection. The VNCs were then subjected to homogenization and differential centrifugation to isolate plasma membrane, mitochondrial, and microsomal fractions. Results indicate that the plasma membrane fraction contained the greatest amount of [ 14 C]DDT, with the mitochondrial and microsomal fractions containing significantly less. Calculations and a comparison with I 50 values for oligomycin‐sensitive (OS)Mg‐ATPase from the literature support the prediction that an insufficient amount of DDT reaches the ventral nerve cord mitochondria of a cockroach to effect an I 50 level of inhibition of the (OS)Mg‐ATPase.