Cis-[Cr(C(2)O(4))(pm)(OH(2))(2)](+) Coordination Ion as a Specific Sensing Ion for H(2)O(2) Detection in HT22 Cells

The purpose of this study was to examine the application of the coordinated cis-[Cr(C(2)O(4))(pm)(OH)(2)](+) cation where pm denotes pyridoxamine, as a specific sensing ion for the detection of hydrogen peroxide (H(2)O(2)). The proposed method for H(2)O(2) detection includes two key steps. The first step is based on the nonenzymatic decarboxylation of pyruvate upon reaction with H(2)O(2), while the second step is based on the interaction of cis-[Cr(C(2)O(4))(pm)(OH(2))(2)](+) with the CO(2) released in the previous step. Using this method H(2)O(2) generated during glutamate-induced oxidative stress was detected in HT22 hippocampal cells. The coordination ion cis-[Cr(C(2)O(4))(pm)(OH(2))(2)](+) and the spectrophotometric stopped-flow technique were applied to determine the CO(2) concentration in cell lysates, supernatants and cell-free culture medium. Prior to CO(2) assessment pyruvate was added to all samples studied. Pyruvate reacts with H(2)O(2) with 1:1 stoichiometry, and consequently the amount of CO(2) released in this reaction is equivalent to the amount of H(2)O(2).