Kinetics of [18F]1-fluoro-2,4-dinitrobenzene,a potential probe for the glutathione detoxification system,in perfused working rat heart

[¹⁸F]1-Fluoro-2,4-dinitrobenzene (FDNB), a substrate for the detoxification enzyme glutathione-S-transferase, was prepared by ¹⁸F-Cl exchange. It was administered as a rapid bolus in the perfused working rat heart and the kinetics of the label were followed by external coincidence detection and by analysis of the coronary effluents and tissue homogenates. The data suggest that part of the extracted tracer was released, part was dehalogenated and part was reversibly incorporated into a large tissue pool of FDNB that was not a substrate for defluorination. The rates of the specific processes, estimated from the residue data, may be sensitive to changes in the glutathione detoxification system and therefore applicable to investigation of the compromised myocardium.