These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Alpha-tocopherol but not beta-tocopherol inhibits thrombin-induced PKC activation and endothelin secretion in endothelial cells.
    Author: Martin-Nizard F, Boullier A, Fruchart JC, Duriez P.
    Journal: J Cardiovasc Risk; 1998; 5(5-6):339-45. PubMed ID: 9920007.
    Abstract:
    INTRODUCTION: Production of endothelin by endothelial cells depends on protein-kinase C (PKC) stimulation which has been reported to be inhibited by alpha-tocopherol (alpha-Toch) but not by beta-tocopherol (beta-Toch). The goal of this study was to determine whether alpha-Toch and beta-Toch inhibit endothelin secretion by endothelial cells. METHODS: and results In a first set of experiments, cultured bovine aortic endothelial cells (BAEC) were incubated for 48h with 100 micromol/l alpha-Toch or vehicle (0.1% ethanol), then cells were stimulated for 4 h or 20 h with thrombin. After stimulating bovine aortic endothelial cells with thrombin for 4 h, alpha-Toch inhibited PKC activity by 63% and endothelin secretion by 44%, whereas after 20 h of incubation with thrombin, alpha-Toch decreased the peptide secretion by 51%. In a second set of experiments, BAEC were incubated with increased concentrations (from 0 to 100 micromol/l) of alpha-Toch or beta-Toch, PKC activity and endothelin secretion were measured after thrombin stimulation as previously reported. In these experiments, alpha-Toch strongly inhibited thrombin-induced PKC activity and endothelin secretion in a dose-dependent manner, whereas beta-Toch was more than 10-fold less active than alpha-Toch in inhibiting these stimulations. Tocopherols (alpha-Toch + beta-Toch) produced a proportional correlation on both PKC stimulation and endothelin secretion by inhibiting the effect of thrombin. CONCLUSION: These data suggest that alpha-Toch strongly inhibits thrombin-induced endothelin secretion in vitro at least partly through PKC inhibition.
    [Abstract] [Full Text] [Related] [New Search]