ABSENCE OF GENERATION OF ACTIVE OXYGEN RADICALS COUPLED WITH PHAGOCYTOSIS BY THE HEMOCYTES OF THE CLAM, RUDITAPES DECUSSATUS (MOLLUSCA, BIVALVIA)

The production of oxygen radicals by hemocytes of Ruditapes decussatus as a cytotoxic mechanism associated with phagocytosis was studied. In vitro phagocytosis assays of yeast cells (zymosan) by clam hemocytes were performed. Two different methods for oxygen radical detection were tested, based on the technique of luminol-dependent chemiluminescence and on the reduction of nitroblue tetrazolium. Hemocytes of the Pacific oyster, Crassostrea gigas, were used as positive control in the assays, because of their ability to produce oxygen radicals. The results obtained showed that the hemocytes of R. decussatus were not able to produce toxic oxygen radicals during phagocytosis, irrespective of whether yeast cells were opsonized or not. Similar results were obtained with hemocytes of the cockle, Cerastoderma edule. (C) 1994 Academic Press, Inc.