SUPEROXIDE RADICAL PRODUCTION BY SPONGES SYCON SP

Using the catechol Tiron as an O-2(-.) scavenger, we showed that sea s ponges (Sycon sp.) produce superoxide radicals in sea mater at a high rate without any stimuli added. The rate of O-2(-.) outflow from spong es to their water surroundings reaches a value of 0.5 nmol/min per spo nge at pH 6.5. The generation of O-2(-.) mas inhibited by Cu,Zn-supero xide dismutase, and restored by the addition of KCN. We also confirmed the abiotic production of O-2(-.) in sea water, detected earlier with a different method by Petasne and Zika [Nature 325 (1987) 516-518]. ( C) 1998 Federation of European Biochemical Societies.