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 mas s have been investigated on splenocytes from control and vit. E defici ent rats, stimulated to proliferate with Concanavalin A, in the presen ce and absence of reduced glutathione (GS H, 5 mM). Rhodamine-123 (Rh- 123) and nonyl acridine orange (NAG) were used as specific probes to m onitor the membrane potential and mass of mitochondria, respectively, by means of flow cytometry. Rh-123 uptake was high in an increasing nu mber of cells from normally fed animals during the three-day culture p eriod. On the contrary, splenocytes from vitamin E deficient rats show ed a biphasic pattern. The number of cells showing a high uptake of Rh -123 increased after 24 hrs. from mitogenic stimulation, then it decre ased at the other two time points considered. In parallel, a continuou s increase of the number of cells with depolarized organelles (up to 6 0% 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 mito chondria, whereas the number of splenocytes with depolarized organelle s did not exceed 17%, irrespective of the diet applied to the animals. The same pattern was observed considering the changes of mitochondria l mass, measured using NAO as a probe. Present results support that GS H may substitute vitamin E in protecting mitochondria from peroxidativ e damage.