Evaluation of the activity of chlorine-containing pesticides as inhibitors of the mitochondrial respiratory chain.

The influence of chlorine-containing pesticides, which are representatives of various classes of chemical compounds and possess various pesticidal activities, on the NAD . H oxidase activity of the submitochondrial particles (SMP) obtained from beef heart was studied. It was found that the strongest inhibitors of NAD . H oxidase of the SMP are chloro-derivatives of aromatic hydrocarbons (DDT and its analogs DDD and DDE). Derivatives of propionic and acetic acids (propinate, dalapon, MCAA, DCAA, and TCAA) did not exhibit any appreciable inhibiting effect under the experimental conditions. Criteria were introduced (phi and Ca50) permitting a quantitative characterization of the influence of pesticides on the respiratory chain of the mitochondria. Indications were obtained of possible mechanisms of the inhibiting action of the pesticides used.