[Alpha-tocopherol prevents thymocyte death induced by antimycin A and oligomycin in rats]

The influence of a-tocopherol, its structure analogues--alpha-tocopheryl acetate and a-tocopheryl quinone, ubiquinone (Q10), and also antioxidants quercetin and N-acetyl-L-cysteine on rat thymocytes apoptosis and necrosis induced by antimycin A and oligomyci, accordingly, was investigated. It was established that alpha-tocopherol completely restored the thymocytes survival independent of production of reactive oxygen species (ROS) by them. The degree of inhibition of ROS generation by the antioxidants having different antiradical activity did not correlate with their influence on thymocytes survival. Quercetin and N-acetyl-L-cysteine reducing, to the greatest degree, the ROS level rendered the least effect on cell survival. Taken together, these results demonstrate that the ability of alpha-tocopherol to effectively prevent the rat thymocytes antimycin A- and oligomycin-induced death is not determined by its antioxidant activity, but is possibly conditioned by prevention of mitochondrial dysfunction by stabilisation of mitochondrial membranes and modulation ofbioenergetic processes.