[Perspectives of in-situ measuring of oxygen free radicals]. / Perspectives de mesure in situ des radicaux libres de l'oxygène.

It has been proposed that the oxygen free radicals (superoxide and hydroxyl radicals), could be partially responsible for the appearance of cellular alterations in the course of various pathological situations. It has not been possible to measure these kinds of radicals because of their very short life span and the very low concentrations present in the tissues. The paramagnetic electronic resonance (PER), of which the principle lies on the specific detection of free radicals, proves, however, to be ill suited for the measurement of the oxygen free radicals, because of an insufficient sensitivity. This sensitivity may be increased with the "spin trapping" technique, the principle of which is to use a trapping component able to be associated to the unstable radical to form a stable product, which accumulates then in the tissues up to a concentration higher than the detection threshold in PER.