[Various characteristics of lipid metabolism of Bacillus brevis var. G.-B]. / Nekotorye osobennosti lipidnogo obmena Bacillus brevis var. G.-B.

Some characteristic features of the lipid metabolism of Bacillus brevis var. G.-B. natural variants and Bacillus brevis mutant 101 were studied. The authors found that upon submerged cultivation gramicidine S-producing P+-variant and B. brevis mutant 101 synthesized higher amounts of tocopherols as compared to other colonial-morphological variants. The highest tocopherol content was observed in P+-variant, whose cells contained the highest amount of total lipids as compared to other gramicidine S-producers.

[Lipid peroxidation and retinal damage in stress]. / Perekisnoe okislenie lipidov i povrezhdenie setchatki pri stresse.

It is shown that in rats exposed to emotional-pain stress, the electric activity of the retina is inhibited (the magnitude of electroretinogram waves is lowered). At the same time the products of lipid peroxidation accumulate and the content of the natural antioxidant alpha-tocopherol decreases in the retina. Preliminary administration to the animals of synthetic antioxidants (4-methyl-2,6-ditretbutylphenol, OP-6 belonging to the hydroxypyridine series) prevents the accumulation of lipid peroxidation products and protects the electric activity of the retina.

[Mechanisms of stabilizing effect of vitamin E against lipid peroxidation in biological membranes]. / Stabiliziruiushchee deistvie vitamina E na biologicheskie membrany pri perekisnom okislenii lipidov.

Mechanisms of the inhibitory effect of vitamin E on the process of lipid peroxidation (LPO) in biological membranes are studied. Both alpha-tocopherol and its derivatives (a-tocopherylacetate, o- and p-tocopherylquinones possess no radical scavenging activity) inhibit non-enzymatic (Fe2+ + ascorbate)-induced LPO and prevent LPO-dependent inhibition of Ca2+ transport in sarcoplasmic reticulum membranes from skeletal muscles. The protective effect of alpha-tocopherylacetate, tocopherilquinones and partially of alpha-tocopherol is due to a stabilizing effect of these compounds on sarcoplasmic reticulum membranes, registered by a decrease of fluidity of membrane lipid bilayer (probed by nitroxile radical TEMPO) and by a decrease of its passive permeability for Ca2+. Under the enzymatic NADPH-dependent LPO induction in rat liver microsomal fraction a strong inhibitory effect of tocopherylquinones is similar to the effect of other electron acceptors (methylnaphtoquinone, TEMPO) and is due to their ability to compete with LPO reaction for reducing equivalents in NADPH-dependent electron carriers wich results in the formation of hydroxy-derivatives having pronounced radical scavenging activity.

[Damage to the sarcoplasmic reticulum of skeletal muscles in leukemia: role of lipid peroxidation]. / Povrezhdenie sarkoplazmaticheskogo retikuluma skeletnykh myshts pri ishemii: rol' perekisnogo okisleniia lipidov.

Ischemia development was accompanied by inhibition of the enzymatic transport system (ETS) of Ca2+ (reduction of the Ca2+/ATP value and of the Ca2+-dependent ATPase activity), this correlating with the accumulation of primary and secondary molecular products of lipid peroxidation (LPO) in the sarcoplasmic reticulum membranes of the skeletal muscles, in vivo. Administration of antioxidants (2,6-ditretbutyl-4-methylphenol, alpha-tocopherol) prevented the LPO activation in the ischemic muscle and partially protected the ETS of Ca2+ from damage. The blood supply restoration after prolonged ischemia led to further ETS of Ca2+ inhibition against the background of unchanges LPO products level.