Effect of Tordon 2,4-D 64/240 triethanolamine BR on the energy metabolism of rat liver mitochondria.
Tordon herbicide, which is a mixture of 4-amino-3,5,6-trichloropicolinic acid (picloram) and 2,4-dichlorophenoxyacetic acid (2,4-D), depresses the phosphorylation efficiency of the rat liver mitochondria, as inferred from the decrease of the respiratory control coefficient and the ADP/O ratios when NAD(+)-dependent substrates were used; NADH oxidase and NADH cytochrome c reductase were also inhibited, without any effect on the other enzymatic complexes of the respiratory chain. Tordon (66.2 nmol picloram + 270 nmol 2,4-D mg-1 protein) affected the amplitude of swelling induced by glutamate, succinate, (N,N,N',N'-tetramethyl-p-phenyldiamine + sodium ascorbate and ATP. These results characterize an interaction of Tordon with complex I of the respiratory chain and also a partial collapse of the proton motive force of the mitochondrial inner membrane without affecting its elasticity.
Pereira
L F
LF
Departamento de Bioquímica, Universidade Federal do Paraná, Curitiba, PR Brasil.
Campello
A P
AP
Silveira
O
O
D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects*; D006540:Herbicides / Q000633:toxicity*; D066298:In Vitro Techniques; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008933:Mitochondrial Swelling / Q000187:drug effects; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D010846:Picloram / Q000633:toxicity*; D014176:Protein Biosynthesis; D051381:Rats
D006540:Herbicides; C048361:sangor; D015084:2,4-Dichlorophenoxyacetic Acid; D010846:Picloram