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Mitochondrial involvement in cocaine‐treated rat hepatocytes: effect of N‐acetylcysteine and deferoxamine
Author(s) -
Zaragoza Asunción,
DíezFernández Carmen,
Alvarez Alberto M,
Andrés David,
Cascales María
Publication year - 2001
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0703909
Subject(s) - cytochrome c , apoptosis , deferoxamine , cytotoxicity , acetylcysteine , mitochondrion , dna fragmentation , chemistry , reactive oxygen species , pharmacology , cytosol , caspase , microbiology and biotechnology , caspase 3 , biochemistry , programmed cell death , biology , in vitro , antioxidant , enzyme
The cytotoxicity of cocaine (0–1000 μ M ), was studied on parameters related to the mitochondrial role and the cascade of events that lead to apoptosis in hepatocyte cultures from phenobarbitone (PB) pretreated rats. Cytotoxicity was dose‐dependent and LDH leakage was significantly enhanced above 100 μ M cocaine. Apoptosis was visualized by DNA fragmentation on agarose gel, and appeared at 50 and 100 μ M cocaine. Cocaine induced biphasic changes in mitochondrial transmembrane potential and significantly increased the mitochondrial release of cytochrome c , the caspase‐3 like DEVDase activity and the level of 20 kDa subunit, a product of pro‐caspase‐3 cleavage. The protective effect of N‐acetylcysteine (NAC) and deferoxamine (DFO) on all these parameters confirmed the involvement of oxygen radicals in cocaine‐induced necrosis/apoptosis. We conclude: first, that the biphasic changes recorded in mitochondrial inner membrane potential by the effect of cocaine, were parallel to apoptosis; second, that caspase‐3 activity and cleavage to it p20 subunit increased sharply in parallel to the translocation of cytochrome c from mitochondria to cytosol; and third, that the antioxidants, NAC or DFO exerted a noticeable protective role in counteracting the cytotoxicity of cocaine, these effects being more pronounced in the case of DFO than NAC. These findings demonstrate that cocaine cytotoxicity involves mitochondrial damage.British Journal of Pharmacology (2001) 132 , 1063–1070; doi: 10.1038/sj.bjp.0703909