Effects of phthalate esters on mitochondrial oxidative phosphorylation in the rat

Abstract

Effects of Phthalate Esters on Mitochondrial Oxidative Phosphorylation in the Rat. Inouye, B., Ogino, Y., Ishida, T., Ogata, M., and Utsumi, K. (1978). Toxicol. Appl. Pharmacol. 43, 189–198. The effects of phthalate esters on oxidative phosphorylation and related functions of isolated rat liver mitochondria were examined. Of the phthalate esters examined, di-n-propylphthalate ester, di-isopropyl phthalate ester, di-n-butyl phthalate ester (DNBP), and di-isobutyl phthalate ester, strongly inhibited both respiratory control and ADP:O ratio with increasing state 4 respiration and decreasing state 3 respiration. DNBP also activated the mitochondrial latent ATPase activity. DNBP induced K+ release from mitochondria, suggesting its interaction with the mitochondrial membrane and causing a change in permeability to ions. It was concluded that DNBP primarily acts as an uncoupler of the mitochondrial oxidative phosphorylation rather than as an electron transport or an energy transfer inhibitor.