The impairment of mitochondrial membrane potential and mass in proliferating lymphocytes from vitamin E deficient animals is recovered by glutathione.

The time-dependent changes of mitochondrial membrane potential and mass have been investigated on splenocytes from control and vit. E deficient rats, stimulated to proliferate with Concanavalin A, in the presence and absence of reduced glutathione (GSH, 5 mM). Rhodamine-123 (Rh-123) and nonyl acridine orange (NAO) were used as specific probes to monitor the membrane potential and mass of mitochondria, respectively, by means of flow cytometry. Rh-123 uptake was high in an increasing number of cells from normally fed animals during the three-day culture period. On the contrary, splenocytes from vitamin E deficient rats showed a biphasic pattern. The number of cells showing a high uptake of Rh-123 increased after 24 hrs. from mitogenic stimulation, then it decreased at the other two time points considered. In parallel, a continuous increase of the number of cells with depolarized organelles (up to 60% by 72 hrs.) has been observed in vit. E deficiency. This impairment was fully prevented by GSH supplementation to the culture medium. In the presence of the thiol, about 80-85% of cells showed activated mitochondria, whereas the number of splenocytes with depolarized organelles did not exceed 17%, irrespective of the diet applied to the animals. The same pattern was observed considering the changes of mitochondrial mass, measured using NAO as a probe. Present results support that GSH may substitute vitamin E in protecting mitochondria from peroxidative damage.