Age Modulates Fe3 O4 Nanoparticles Liver Toxicity: Dose-Dependent Decrease in Mitochondrial Respiratory Chain Complexes Activities and Coupling in Middle-Aged as Compared to Young Rats

• Published in: BioMed research international Vol. 2014
• Main Authors: Baratli, Yosra, Charles, Anne-Laure, Wolff, Valerie, Ben Tahar, Lotfi, Smiri, Leila, Bouitbir, Jamal, Zoll, Joffrey, Sakly, Mohsen, Auger, Cyril, Vogel, Thomas, Abdelmelek, Hafedh, Tebourbi, Olfa, Geny, Bernard
• Format: Journal Article
• Language: English
• Published: 01.01.2014
• ISSN: 2314-6133; 2314-6141
• DOI: 10.1155/2014/474081

We examined the effects of iron oxide nanoparticles (IONPs) on mitochondrial respiratory chain complexes activities and mitochondrial coupling in young (3 months) and middle-aged (18 months) rat liver, organ largely involved in body iron detoxification. Isolated liver mitochondria were extracted using differential centrifugations. Maximal oxidative capacities ( sub(Vmax) , complexes I, III, and IV activities), sub(Vsucc) (complexes II, III, and IV activities), and sub(Vtmpd) , (complex IV activity), together with mitochondrial coupling ( sub(Vmax) / sub(V0) ) were determined in controls conditions and after exposure to 250, 300, and 350 mu g/ml Fe sub(3) O sub(4) in young and middle-aged rats. In young liver mitochondria, exposure to IONPs did not alter mitochondrial function. In contrast, IONPs dose-dependently impaired all complexes of the mitochondrial respiratory chain in middle-aged rat liver: sub(Vmax) (from 30 plus or minus 1.6 to 17.9 plus or minus 1.5; P<0.001 ), sub(Vsucc) (from 33.9 plus or minus 1.7 to 24.3 plus or minus 1.0; P<0.01 ), sub(Vtmpd) (from 43.0 plus or minus 1.6 to 26.3 plus or minus 2.2 mu mol O sub(2) /min/g protein; P<0.001 ) using Fe sub(3) O sub(4) 350 mu g/ml. Mitochondrial coupling also decreased. Interestingly, 350 mu g/ml Fe sub(3) O sub(4) in the form of Fe super(3+) solution did not impair liver mitochondrial function in middle-aged rats. Thus, IONPs showed a specific toxicity in middle-aged rats suggesting caution when using it in old age.