[Stabilization of synaptic membranes with alpha-tocopherol against the damaging effect of phospholipases. Possible mechanism of the biological action of vitamin E].
Using fluorescent and EPR spin probing techniques, the effects of phospholipases A2, C and D on rat brain synaptosomal membranes were investigated. It was shown that treatment of synaptosomal membranes with phospholipases A2, C and D results in their depolarization and increase of their surface negative charge. In case of phospholipases A2 and C, these changes are also accompanied by a decrease of the microviscosity of the synaptosomal membrane lipid bilayer. alpha-Tocopherol protects synaptosomal membranes against the damaging action of phospholipases. The stabilization of synaptosomes by vitamin E consists in the reconstitution of the transmembrane potential and in an increased microviscosity of phospholipase-treated membranes. The stabilizing effect of alpha-tocopherol is due to the binding of phospholipid hydrolysis products rather than to the inhibition of phospholipases. The observed stabilization of synaptosomal membranes by alpha-tocopherol is interpreted as a feasible mechanism of biological effects of vitamin E on biological membranes.
Erin
A N
AN
Gorbunov
N V
NV
Brusovannik
V I
VI
Tiurin
V A
VA
Prilipks
L L
LL
D000818:Animals; D001921:Brain / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D007700:Kinetics; D008560:Membrane Fluidity / Q000187:drug effects*; D010740:Phospholipases / Q000037:antagonists & inhibitors*; D051381:Rats; D011919:Rats, Inbred Strains; D013570:Synaptic Membranes / Q000187:drug effects / Q000378:metabolism*; D014810:Vitamin E / Q000494:pharmacology*
D005456:Fluorescent Dyes; D014810:Vitamin E; D010740:Phospholipases
Stabilizatsiia sinapticheskikh membran alpha-tokoferolom ot povrezhdaiushchego deĭstviia fosfolipaz. Vozmozhnyĭ mekhanizm biologicheskogo deĭstviia vitamina E.