4,6-dinitro-o-cresol uncouples oxidative phosphorylation and induces membrane permeability transition in rat liver mitochondria

被引:22
作者
Castilho, RF [1 ]
Vicente, JAF [1 ]
Kowaltowski, AJ [1 ]
Vercesi, AE [1 ]
机构
[1] UNIV COIMBRA,FAC CIENCIAS & TECNOL,DEPT ZOOL,P-3049 COIMBRA,PORTUGAL
关键词
calcium ion; cyclosporin A; 4,6-dinitro-o-cresol; mitochondria; mitochondrial respiration; mitochondrial permeability transition; protonophore;
D O I
10.1016/S1357-2725(97)00041-1
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The effect of the herbicide 4,6-dinitro-o-cresol (DNOC), a structural analogue of the classical protonophore 2,4-dinitrophenol, on the bioenergetics and inner membrane permeability of isolated rat liver mitochondria was studied. We observed that DNOC (10-50 mu M) acts as a classical uncoupler of oxidative phosphorylation in rat liver mitochondria, promoting both an increase in succinate-supported mitochondrial respiration in the presence or absence of ADP and a decrease in transmembrane potential. The protonophoric activity of DNOC was evidenced by the induction of mitochondrial swelling: in hyposmotic Kf-acetate medium, in the presence of valinomycin. At higher concentrations (> 50 mu M), DNOC also induces an inhibition of succinate-supported respiration, and a decrease in the activity of the succinate dehydrogenase can be observed. The addition of uncoupling concentrations of DNOC to Ca2+-loaded mitochondria treated with Ruthenium Red results in non-specific membrane permeabilization, as evidenced by mitochondrial swelling in isosmotic sucrose medium. Cyclosporin A, which inhibits mitochondrial permeability transition, prevented DNOC-induced mitochondrial swelling in the presence of Ca2+, which was accompanied by a decrease in mitochondrial membrane protein thiol content, owing to protein thiol oxidation. Catalase partially inhibits mitochondrial swelling and protein thiol oxidation, indicating the participation of mitochondrial-generated reactive oxygen species in this process. It is concluded that DNOC is a potent protonophore acting as a classical uncoupler of oxidative phosphorylation in rat liver mitochondria by dissipating the proton electrochemical gradient. Treatment of Ca2+-loaded mitochondria with uncoupling concentrations of DNOC results in mitochondrial permeability transition, associated with membrane protein thiol oxidation by reactive oxygen species. Copyright (C) 1997 Elsevier Science Ltd.
引用
收藏
页码:1005 / 1011
页数:7
相关论文
共 26 条
[1]   SAFRANINE AS A PROBE OF MITOCHONDRIAL-MEMBRANE POTENTIAL [J].
AKERMAN, KEO ;
WIKSTROM, MKF .
FEBS LETTERS, 1976, 68 (02) :191-197
[2]  
BERNARDI P, 1992, J BIOL CHEM, V267, P8834
[3]   INDUCTION OF BIOTRANSFORMATION IN THE LIVER OF EEL (ANGUILLA-ANGUILLA L) BY SUBLETHAL EXPOSURE TO DINITRO-O-CRESOL - AN ULTRASTRUCTURAL AND BIOCHEMICAL-STUDY [J].
BRAUNBECK, T ;
VOLKL, A .
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 1991, 21 (02) :109-127
[4]   OXIDATIVE DAMAGE OF MITOCHONDRIA INDUCED BY FE(II)CITRATE IS POTENTIATED BY CA2+ AND INCLUDES LIPID-PEROXIDATION AND ALTERATIONS IN MEMBRANE-PROTEINS [J].
CASTILHO, RF ;
MEINICKE, AR ;
ALMEIDA, AM ;
HERMESLIMA, M ;
VERCESI, AE .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1994, 308 (01) :158-163
[5]   PERMEABILIZATION OF THE INNER MITOCHONDRIAL-MEMBRANE BY CA2+ IONS IS STIMULATED BY T-BUTYL HYDROPEROXIDE AND MEDIATED BY REACTIVE OXYGEN SPECIES GENERATED BY MITOCHONDRIA [J].
CASTILHO, RF ;
KOWALTOWSKI, AJ ;
MEINICKE, AR ;
BECHARA, EJH ;
VERCESI, AE .
FREE RADICAL BIOLOGY AND MEDICINE, 1995, 18 (03) :479-486
[6]  
CASTILHO RF, 1996, J BIOENERG BIOMEMBR, V29, P523
[7]  
Ellman GL, 1959, ARCH BIOCHEM BIOPHYS, V82, P70, DOI DOI 10.1016/0003-9861(59)90090-6.PMID:13650640
[8]  
GRIFFITHS EJ, 1995, BIOCHEM J, V307, P109
[9]   MECHANISMS BY WHICH MITOCHONDRIA TRANSPORT CALCIUM [J].
GUNTER, TE ;
PFEIFFER, DR .
AMERICAN JOURNAL OF PHYSIOLOGY, 1990, 258 (05) :C755-C786
[10]   CHARACTERISTICS OF FE(II)ATP COMPLEX-INDUCED DAMAGE TO THE RAT-LIVER MITOCHONDRIAL-MEMBRANE [J].
HERMESLIMA, M ;
CASTILHO, RF ;
MEINICKE, AR ;
VERCESI, AE .
MOLECULAR AND CELLULAR BIOCHEMISTRY, 1995, 145 (01) :53-60