[Mechanism of stabilization of synaptosomes with alpha-tocopherol during exposure to phospholipase A2].
Changes in potential-dependent fluorescence were studied, using fluorescent probe di-S-C3-(5), in synaptosome suspensions exposed to phospholipase A2, alpha-tocopherol and its derivatives. Phospholipase A2 increased potential-dependent fluorescence, i.e. depolarization of synaptosome membranes. The damaging phospholipase A2 effect was prevented and/or abolished by alpha-tocopherol added to synaptosome suspensions before and after phospholipase A2. Alpha-tocopherol derivatives (2,2,5,7,8-pentamethyl-6-hydroxychromane and alpha-tocopheryl-acetate as well as 4-methyl-2,6-di-tert-butylphenol) failed to exert a protective effect on synaptosome membranes modified by phospholipase A2. It is suggested that alpha-tocopherol effect is determined by its interaction with fatty acids, with 6-hydroxy groups of chromanol nucleus and phytol chain being essential for the complex formation.
D000818:Animals; D001921:Brain / Q000648:ultrastructure*; D066298:In Vitro Techniques; D010740:Phospholipases / Q000037:antagonists & inhibitors*; D010741:Phospholipases A / Q000037:antagonists & inhibitors* / Q000633:toxicity; D054467:Phospholipases A2; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000187:drug effects*; D014810:Vitamin E / Q000494:pharmacology*
D014810:Vitamin E; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2
Mekhanizm stabilizatsii sinaptosom al'fa-tokoferolom pri deĭstvii fosfolipazy A2.