An assay for the rate of removal of extracellular hydrogen peroxide by cells

作者：Wagner Brett A; Witmer Jordan R; van' t Erve Thomas J; Buettner Garry R^*

来源：Redox Biology, 2013, 1(1): 210-217.

DOI：10.1016/j.redox.2013.01.011

• Hydrogen peroxide
• Kinetics
• Erythrocyte
• Quantitative redox biology

Cells have a wide range of capacities to remove extracellular hydrogen peroxide. Al higher concentrations of extracellular H2O2 (micromolar) the rate of removal can be approximated by a rate equation that is first-order in the concentration of H2O2 and cell density. Here we present a method to determine the observed rate constant for the removal of extracellular H2O2 on a per cell basis. In the cells examined, when exposed to 20 mu M H2O2, these rate constants (k(cell)) range from 0.46 x 10(-12) s(-1) cell(-1) for Mia-PaCa-2 cells (human pancreatic carcinoma) to 10.4 x 10(-12) s(-1) cell(-1) L for 1J937 cells (human histiocytic lymphoma). For the relatively small red blood cell k(cell)=2.9 x 10(-12) s(-1) cell(-1) L. These rate constants, k(cell), can be used to compare the capacity of cells to remove higher levels of extracellular H2O2, as often presented in cell culture experiments. They also provide a means to estimate the rate of removal of extracellular H2O2, rate= -k(cell) [H2O2] (cells L-1), and the half-life of a bolus of H2O2. This information is essential to optimize experimental design and interpret data from experiments that expose cells to extracellular H2O2.

• 出版日期2013