Effects of pesticides on isolated rat hepatocytes, mitochondria, and microsomes

Abstract

Twenty-seven pesticides, with which people are concerned, especially as residues in food, were examined in vitro for their effects on hepatocytes, mitochondria, and microsomes isolated from male rats. Nineteen pesticides returned non-protein sulfhydryl (NPSH) contents in hepatocytes to less than 80% of control at concentrations from 10⁻³ to 10⁻⁵ M after 90 min incubation. Among them, only dichlofluanid was reactive with glutathione non-enzymatically. Lipid peroxidation in hepatocytes was stimulated by five pesticides at 10⁻³ M, with edifenphos being the most potent peroxidant. Cell viability was considerably decreased by incubation with chlorobenzilate, edifenphos, dichlofluanid, and chinomethionat at 10⁻³ M, and in these cases, depletion of cellular adenosine 5′-triphosphate (ATP) contents proceeded to cell death. With respect to isolated mitochondrial respiration, six pesticides inhibited state 3 and/or state 4 respiration rates at concentrations from 10⁻³ to 10⁻⁵ M, whereas three pesticides uncoupled state 4 respiration at 10⁻³ M. With respect to isolated microsomal lipid peroxidation, seven pesticides, five of which were organophosphorus compounds, were peroxidative at concentrations from 10⁻³ to 10⁻⁵ M, whereas seven pesticides were antioxidative at concentrations from 10⁻³ to 10⁻⁷ M. Only three pesticides, aldicarb, maleic hydrazide, and chlormequat chloride had no effect on any parameters tested at 10⁻³ M. Pesticides that affected isolated mitochondria or microsomes did not necessarily have any effect on isolated hepatocytes.