[The cytotoxicity of Chamaenerium angustifolium (L.) Scop. and Hippophae rhamnoides L. tannins and their effect on mitochondrial respiration]. / Tsitotoksichnost' tanninov Chamaenerium angustifolium (L.) Scop. i Hippophae rhamnodies L. i ikh vliianie na dykhanie mitokhondrii.

The cytotoxic activity of complexes of hydrolysable tannins of Chamaenerium angustifolium L. Scop. and Hippophae rhamnoides L. was compared with that of the antineoplastic drugs vinoblastin (VLB), methotrexate (MT), and 5-fluorouracil (5-FU). The tannins yield to VLB and MT in activity but resemble 5-Fu in their active concentration. They inhibited succinate oxidation by the rat liver mitochondria and their cytotoxicity was displayed in much lower concentrations than their inhibitory effect on mitochondrial respiration. It is concluded that tannins inhibit the respiratory chain at the third point of conjugation in the transfer of electrons from cytochrome c to oxygen.

Effect of superoxide in air on structural organization and phosphorylating respiration of mitochondria.

The effect of negative air ions generated by a Tchijevsky lustre was studied in rat liver mitochondria in homogenate under conditions providing preservation of their native structural organization in the form of associations. Rapid formation of large associations from intermediate and small associations occurs after the homogenate was put into medium pretreated by negative air ions (NAI). Under the influence of a flow of NAI on mitochondria stored on ice for 2-3 h formation of giant associations is observed. Associations of mitochondria are not dissipated by stirring with a magnetic stirrer for several minutes. The influence of medium pretreated with NAI or flow of NAI on homogenate improves weakened respiratory energy control and restores stimulation of phosphorylating respiration by adrenalin administration. The improvement of phosphorylation in mitochondria by NAI is perhaps caused by more complete preservation of both their native structural organization and related physiological regulation of mitochondrial processes in isolated preparations.

[Monoamine oxidase activity in rat liver in vitamin B12 deficiency]. / Monoaminooksidaznaia aktivnost' v pecheni krys pri nedostatochnosti vitamina B12.

Changes in the activity of monoamine oxidase (MAO-B) in liver homogenates and mitochondria from normal and vitamin B12-deficient rats have been studied in various functional states of the mitochondria. Preincubation of liver preparation at 32 degrees C increased the MAO affinity for benzylamine in samples of normal (but not vitamin B12-deficient rats). Succinate added to the incubation medium decreased Km and increased Vmax in both normal and vitamin B12-deficient animals. A correlation was found between the decline of MAO-B activity under vitamin B12 deficiency, deceleration of succinate oxidation and reduction of the transmembrane potential.

[Effect of GDP and carboxyatractylate on potassium ion transport in brown fat mitochondria]. / Vliianie GDP i karboksiatraktilata na transport ionov kaliia v mitokhondriiakh burogo zhira.

It has been shown that the increase of the membrane potential in uncoupled brown fat mitochondria after addition of 1-2 mM GDP to a medium containing potassium acetate is accompanied by swelling of mitochondria which occurs in two phases. The first swelling phase is due to the electrogenic transport of K+ ions, while the second one is activated by carboxyatractylate and carnitine. The swelling is practically completely inhibited by a further rise of the GDP concentration irrespective of high values of the membrane potential. Unlike K+ transport, the potential-dependent transport of Na+ ions occurs more rapidly, is monophasic and insensitive to carboxyatractylate and carnitine. It is suggested that regulation of K+ ion transport in brown fat mitochondria is mediated by the action of nucleotides and fatty acid esters on the uncoupling protein and ADP/ATP antiporter.

[2 mechanisms of membrane electroconductivity with tetrachloro-2-trifluoromethylbenzimidazole (TTFB)]. / Dva mekhanizma élektroprovodnosti membran s tetrakhlor-2-triftormetilbenzimidazolom (TTFB)

It has been found during galvanostatic measurements under the conditions of diffusion overtension that charge transfer through the membrane is carried out by the transfer of a proton from a neutral form to an anion (acidic region), or by transfer of a negative charge--dimer due to the formation of a hydrogen bond between them on the membrane border (alkaline region).