Effect of reduced glutathione on mitochondrial parameters of proliferating splenocytes from young and old rats

The time-dependent changes of mitochondrial membrane potential and mass have been investigated on splenocytes from young, adult and old rats stimulated with Con A in the presence and absence of reduced glutathione (GSH). In addition, the basal level as well as the level of GSH during a 3-day culture period has been determined. No age-dependent changes of cellular GSH content were observed in freshly prepared splenocytes; however, in proliferating cells from old animals the expected increase in GSH levels was delayed. As regards the mitochondrial parameters, their membrane potential and mass were measured by means of the fluorescent probes rhodamine-123 (Rh-123) and nonyl acridine orange (NAO), respectively, and flow cytometry. During aging and with time of culture, an increased number of cells showed depolarization and loss of mitochondrial mass. This age-dependent impairment was completely prevented by addition of GSH to the culture medium, which resulted in a sharp increase in intracellular GSH. The present findings support the view that an impairment of the antioxidant defense system may be responsible for the damage observed in the mitochondria of proliferating splenocytes from old animals.