Use of a voltage-responsive timer to quantitate hydroperoxides by the cyclooxygenase activation assay

The importance of lipid hydroperoxides in the interpretations of physiological and pathological processes requires a valid and reliable microanalytical procedure. However, quantitation of the small amounts of lipid hydroperoxides in biological samples is often attempted with methods that have low sensitivity, low validity, and/or low reliability. The highly sensitive and specific enzymatic assay based upon cyclooxygenase activation has many complex kinetic features that have caused it to be cumbersome and unreliable. Analysis of the cyclooxygenase kinetics showed that a fixed percentage (20%) of full reaction accurately substituted for the measurements of the time required to reach optimal velocity. Consequently, a voltage-responsive timer can report endpoints that are dependent upon picomole amounts of lipid hydroperoxide. Additional features of the timer are described which make the hydroperoxide assay simpler, faster, more reliable, and easier to perform than the previous method while still retaining its sensitivity and specificity.