<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Samhan-Arias, A. K.</style></author><author><style face="normal" font="default" size="100%">Duarte, R. O.</style></author><author><style face="normal" font="default" size="100%">Martin-Romero, F. J.</style></author><author><style face="normal" font="default" size="100%">Moura, J. J.</style></author><author><style face="normal" font="default" size="100%">Gutierrez-Merino, C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Reduction of ascorbate free radical by the plasma membrane of synaptic terminals from rat brain</style></title><secondary-title><style face="normal" font="default" size="100%">Arch Biochem Biophys</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">*Free Radicals</style></keyword><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Ascorbic Acid/*metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Biochemistry/*methods</style></keyword><keyword><style  face="normal" font="default" size="100%">Brain/*metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Membrane/*metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochromes c/metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Edetic Acid/chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">NADPH Oxidase/metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Rats</style></keyword><keyword><style  face="normal" font="default" size="100%">Synapses/*metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Ubiquinone/chemistry</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Jan 15</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&amp;db=PubMed&amp;dopt=Citation&amp;list_uids=17963686 </style></url></web-urls></urls><number><style face="normal" font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">469</style></volume><pages><style face="normal" font="default" size="100%">243-54</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Synaptic plasma membranes (SPMV) decrease the steady state ascorbate free radical (AFR) concentration of 1mM ascorbate in phosphate/EDTA buffer (pH 7), due to AFR recycling by redox coupling between ascorbate and the ubiquinone content of these membranes. In the presence of NADH, but not NADPH, SPMV catalyse a rapid recycling of AFR which further lower the AFR concentration below 0.05 microM. These results correlate with the nearly 10-fold higher NADH oxidase over NADPH oxidase activity of SPMV. SPMV has NADH-dependent coenzyme Q reductase activity. In the presence of ascorbate the stimulation of the NADH oxidase activity of SPMV by coenzyme Q(1) and cytochrome c can be accounted for by the increase of the AFR concentration generated by the redox pairs ascorbate/coenzyme Q(1) and ascorbate/cytochrome c. The NADH:AFR reductase activity makes a major contribution to the NADH oxidase activity of SPMV and decreases the steady-state AFR concentration well below the micromolar concentration range.&lt;/p&gt;
</style></abstract><accession-num><style face="normal" font="default" size="100%">17963686</style></accession-num><notes><style face="normal" font="default" size="100%">&lt;p&gt;1096-0384 (Electronic)0003-9861 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't&lt;/p&gt;
</style></notes><auth-address><style face="normal" font="default" size="100%">Department of Biochemistry and Molecular Biology, Faculty of Sciences, University of Extremadura, 06071 Badajoz, Spain.</style></auth-address></record></records></xml>