Demonstration of the heterogeneity of the intracellular activity of oxidases by quantitative microspectrofluorimetry: comparison of two cell strains

A microspectrofluorimeter has been used for kinetic studies of the decrease of polycyclic aromatic hydrocarbons (PAH) fluorescence in single living cells (3T3 and RTG2 fibroblasts). These studies allow the determination of activation rate constants (k) for PAH. The distribution of the cellular populations has been represented as a function of k. The histograms show: an heterogeneity of the cellular population; differences between the metabolic activities of the two strains; modifications of the metabolization depending upon the probe tested.