Inhibition of Ca2+-induced cytosolic enzyme efflux from skeletal muscle by vitamin E and related compounds.
1. Efflux of an intracellular enzyme (creatine kinase) from normal rat skeletal muscles was induced by treatment with the Ca2+ ionophore A23187. Addition of alpha-tocopherol (230 microM) to the incubation medium was found to significantly diminish this efflux, and this effect was mimicked by alpha-tocopherol acetate, phytol and isophytol, but not by Trolox C (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid). 2. Analysis of muscle cation content has shown that these protective effects of alpha-tocopherol etc. are not due to an inhibition of the Ca2+ accumulating effects of the ionophore. 3. Non-enzymic lipid peroxidation of skeletal-muscle homogenates was found to be inhibited by alpha-tocopherol and Trolox C, partially inhibited by phytol and isophytol, but unaffected by alpha-tocopherol acetate. 4. The activity of lipoxygenase enzymes was partially inhibited by alpha-tocopherol, phytol and isophytol, but not by alpha-tocopherol acetate or Trolox C. 5. Prostaglandin E2 efflux from isolated skeletal muscles was stimulated by treatment with the Ca2+ ionophore, but this was unaffected by alpha-tocopherol treatment.
Phoenix
J
J
Department of Medicine, University of Liverpool, U.K.
Edwards
R H
RH
Jackson
M J
MJ
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002839:Chromans / Q000494:pharmacology; D003402:Creatine Kinase / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology*; D015232:Dinoprostone / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008084:Lipoxygenase / Q000378:metabolism; D009132:Muscles / Q000187:drug effects* / Q000201:enzymology; D010836:Phytol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D024505:Tocopherols; D014810:Vitamin E / Q000031:analogs & derivatives / Q000494:pharmacology*; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
D002839:Chromans; D014810:Vitamin E; D010836:Phytol; D000001:Calcimycin; D008084:Lipoxygenase; D003402:Creatine Kinase; D024502:alpha-Tocopherol; D015232:Dinoprostone; D024505:Tocopherols; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; D002118:Calcium