THE NEW EPR MOLECULAR-OXYGEN PROBE FUSINITE IS NOT TOXIC TO CELLS

The possible cytotoxic effects of fusinite, a new charcoal-like electr on paramagnetic resonance (EPR) oxygen probe, were evaluated in three cell types with very different characteristics and growth features: K5 62 (an erythroleukemic cell line which grows in suspension), A431 (an epidermal carcinoma cell Line which grows in monolayer) and primary cu ltures of murine fibroblasts (which also grow in adhesion culture) uti lizing morphological and functional studies as well as growth analyses . Scanning and transmission electron microscopy as well as fluorescenc e microscopy were used for the morphological analyses while conductome tric relaxation studies in the radiowave frequency range, membrane res istance measurements and adenine nucleotide levels were utilized for t he more subtle functional evaluation of cell parameters. The results s how that the presence of fusinite particles, even after long internali zation times, does not induce any cytotoxic effects in the cells studi ed. Thus, from these results, it can be deduced that fusinite is non-t oxic as well as highly stable, inert and very sensitive to oxygen, and can be used with great success for cell studies where determination o f oxygen concentration is important. (C) 1998 Elsevier Science B.V.