Inhibitory effect of vitamin E succinate on the proliferation of cultured bovine choroidal endothelial cells

We report the effect of vitamin E succinate (VE succinate) on the proliferation of cultured bovine choroidal endothelial cells (BCECs). BCECs were incubated with a medium containing vitamin E (VE) or one of the VE derivatives gamma-tocopherol, VE phosphate, VE succinate, VE nicotinate, VE acetate, or trolox, at a concentration of 10 microM. The proliferation of BCECs was assessed by 3H-thymidine uptake and cell counting. Especially in VE and VE succinate, the proliferation assay was performed on BCECs at two different stages, that is, the proliferating stage and the quiescent stage. The effect of protein kinase C (PKC) stimulator phorbol ester (PMA) on the VE succinate-induced inhibition of BCEC proliferation was also examined. VE succinate was found to significantly inhibit BCEC proliferation at a concentration of 10 microM or greater both by 3H-thymidine uptake assay and by cell counting. This inhibitory effect was not noted in other VE derivatives. The inhibitory effect was the most prominent in the proliferating BCECs and co culture of PMA. VE succinate inhibits the proliferation of cultured BCECs and PKC is involved in this action at least in part.