SPONTANEOUS CHEMILUMINESCENCE OF ETYA (5,8,11,14-EICOSATETRAYNOIC ACID) IS INHIBITED BY CATALASE OR PEROXIDASE

5,8,11,14-eicosatetraynoic acid (ETYA), an isomorphic competitive anal ogue of arachidonic acid, spontaneously generates a chemiluminescence signal detected with a liquid scintillation spectrometer operated at a mbient temperature in the out-of-coincidence mode. The intensity of th e signal was 10- or more-fold above background, required oxygen for it s generation, was inhibited by antioxidants, and approximately doubled in D2O. Arachidonic acid, which contains 4-alkene rather than alkyne bonds did no more than double the chemiluminescent signal above backgr ound. When examined at 37 degrees C in a Berthold AutoLumat 958 lumino meter, DBA (lucigenin) was required to detect a signal above backgroun d. Catalase or peroxidase, and to a lesser extent mannitol or histidin e but not superoxide dismutase, strongly diminished the signal intensi ty. These observations provide a baseline for interpreting the functio nal and electron microscopic changes produced by ETYA in PC3 prostate and A172 glioblastoma cell lines, consistent with a contribution from oxidative stress associated with free radicals, and the absence of the se morphological changes in U937 monoblastoid cells.