Tocopherol transport in the rat erythrocyte

Abstract

A B S T R A C T The transport of vitamin E (a-tocopherol) has been studied in the rat erythrocyte in vivo and in vitro. Uptake and efflux are independent of energy, but sensitive to temperature. Tocopherol is localized to the cell membrane. Rapid exchange takes place between erythrocytes and serum with an hourly fractional tocopherol efflux of 26%. The vitamin is transferred from the erythrocyte to the low density lipoproteins. These experiments indicate that tocopherol, like cholesterol, is a constituent of the erythrocyte membrane which is in dynamic equilibrium with the corresponding plasma compound.

Tocopherol level in human blood cells.

“…The finding that alpha-tocopherol is localized only in the membranes of RBC, is in agreement with CHOW (16) and SILBER (14). CHOW used direct measurement of RBC membranes, while SILBER used isotope-labeled tocopherol.…”

“…In previous reports (11,13,14), the assay was carried out using TLC and/or GLC techniques, and in association, further correction, calculated from the recovery of isotope-labeled tocopherol added at the beginning of procedure, was necessary. The method introducing HPLC, as devised by ABE (7) and ISHIBASHI (8), was used in our study; this gave a simple (15); more than 85% of the total tocopherol was the alpha form, but only a small amount of the gamma form was detected, while no beta or delta-tocopherol was detected.…”

The Effect of Vitamin E on the Immune Response of Hypoxic and Normal Chickens*

“…Among these functions may be the involvement in the cellular development of the hemopoietic-immunopoietic system, the cells of which most likely originate from a common pluripotential stem cell (12). The involvement of vitamin E in the development and population kinetics of erythroid cells has already been demonstrated (3,6,8 Fig. 1 that vitamin E significantly increased the number of AB PFC both at ground level (1,500 m) and at 4,800 m simulated altitude level.…”

“…Further experiments are in progress now to find out the optimal level of vitamin E in the immune response. In the light of these data plus the reports in the literature on the role of vitamin E in erythrocyte regulation (3,6,8) and the common stem cell origin of erythrocyte and lymphoid cells (12), the hypothesis of a direct involvement of vitamin E in immunocyte development and AB regulation is not unlikely, and can be tested experimentally using diets from vitamin E-deficient to fortified, and measuring quantitatively AB biosynthesis and immunocyte kinetics. The synergistic effect observed with the combined vitamin E and altitude treatment suggests that the mechanism of vitamin E action is most likely connected with its antioxidant property; vitamin E combined with hypoxia creates more reducing conditions in the electron transport chain for cellular developmental processes (3).…”

“…Among these functions may be the involvement in the cellular development of the hemopoietic-immunopoietic system, the cells of which most likely originate from a common pluripotential stem cell (12). The involvement of vitamin E in the development and population kinetics of erythroid cells has already been demonstrated (3,6,8). The purpose of the present communication is to show that vitamin E is also involved in the immune response and that the effects of hypoxia and vitamin E on the immune response are synergistic.…”