[Postradiation changes in the functioning of the systems of lipid peroxidation and phospholipase hydrolysis in the cellular formations of the brain]. / Postradiatsionnye izmeneniia funktsionirovaniia sistem perekisnogo okisleniia lipidov i fosfolipaznogo gidroliza v kletochnykh obrazovaniiakh mozga.

A study was made of the effect of irradiation with lethal and superlethal doses on lipid peroxidation and endogenous phospholipase hydrolysis in the enriched fractions of neurons and glia. Severe and irreversible changes occurred in a lipid membrane component of both neuronal and glial fractions of the brain under the effect of ionizing radiation.

[Lipid peroxidation and endogenous phospholipase hydrolysis during trauma and graded hypothermic load]. / Perekisnoe okislenie lipidov i éndogennyi fosfolipaznyi gidroliz v usloviiakh travmy i dozirovannoi gipotermicheskoi nagruzki.

Rates of lipid peroxidation and endogenous phospholipase hydrolysis were studied under conditions of simultaneous moderate hypothermia and traumatic ischemia of muscles. Activation of the reactions studied, which was expressed as an increase in content of malonic dialdehyde and free fatty acids, was of importance for pathogenesis of muscles impairments occurring in trauma. Local cooling affected favourably these patterns of lipid metabolism.

[Postradiation changes of the active ion transport systems of the CNS. Na, K-ATPase of neurons and neuroglia]. / Postradiatsionnye izmeneniia v sistemakh aktivnogo transporta ionov v TsNS. Na, K-ATFaza neironov i neiroglii.

A study was made of the effect of X-radiation (0.31 C/kg and 3.875 C/kg) on Na, K-ATPase in fractions enriched with neurons and neuroglia. The results show the impairment of the neuronal-glial relationship in Na, K-ATPase activity. The most important differences in the pattern of changes in Na, K-ATPase system of brain cells were followed up after irradiation with lethal and sublethal doses.

[Postradiation changes of active ion transport systems of the CNS. The effect of superlethal doses of ionizing radiation on the Na,K pump in surviving brain slices]. / Postradiatsionnye izmeneniia v sistemakh aktivnogo transporta ionov v TsNS. Vliianie sverkletal'nykh doz ioniziruiushchei radiatsii na Na,K-nasos v perezhivaiushchikh srezakh mozga.

Active potassium ion transport in surviving sections of rat brain was irreversibly inhibited 6 min, 1 h and 6 h following whole-body single X irradiation. At the same time, the accumulation of products of lipid peroxidation and phospholipase hydrolysis was followed up during the development of radiation pathology. The relationship was noted between the postirradiation changes in the physicochemical status of lipids of the membrane and the impairment of its transport function.

[The action of ionizing radiation on neuronal function in the edible snail. Phospholipase A2 and the Na+ and K+ transport systems]. / Deistvie ioniziruiushchei radiatsii na funktsional'noe sostoianie neironov vinogradnoi ulitki. Fosfolipaza A2 i sistemy transporta Na+ i K+.

A study was made of the influence of A2 phospholipase on 22Na release from cells of nerve ganglia of edible snail. The treatment of nerve ganglia with A2 phospholipase inhibits Na, K-pump of neuronal membranes and does not exert a substantial effects on Na/Ca metabolism. There is a similarity between the effects of ionizing radiation and A2 phospholipase on the release of 22Na from cells.

[The effect of ionizing radiation on the regulation of the Na,K-ATPase activity of the kidney by univalent cations]. / Vliianie ioniziruiushchei radiatsii na reguliatsiiu aktivnosti Na,K-ATFazy pochek odnovalentnymi kationami.

The effect of ionizing radiation of 0.206 C/kg on the kinetics of activation of rat kidney Na,K-ATPase preparation by Na and K ions was studied as an index of possible qualitative and quantitative changes in the properties of the enzyme. Ionizing radiation was shown not only to increase the enzyme activity but also to change the optimal rate of ATP hydrolysis by Na,K-ATPase and to induce some differences in the shape of the curve for Na,K-ATPase dependence upon Na-sodium//potassium ion ratio in the incubation medium.

[Postradiation changes in the system of active transport of ions in the CNS. Analysis of the cation centers of Na,K-ATPase]. / Postradiatsionnye izmeneniia v sistemakh aktivnogo transporta ionov v TsNS. Analiz kationnykh tsentrov Na,K-ATFazy.

A study was made of the influence of ionizing radiation of 0.31 C/kg on the kinetic parameters showing the activity of brain Na, K-ATPase preparation to be a function of ion-regulator concentration. The use of the new method for the analysis of the enzyme cation centers permitted to estimate that whole-body irradiation of rats with the above dose did not cause in vitro a substantial change in the pattern of Na, K-ATPase activation by Na and K ions.

[Postradiation changes in the systems of active ion transport in the CNS. Potassium ion reaccumulation by surviving brain slices]. / Postradiatsionnye izmeneniia v sistemakh aktivnogo transporta ionov v TsNS. Reakkumuliatsiia ionov kaliia perezhivaiushchimi srezami mozga.

The data are reported concerning the effects of ionizing radiation (0.155 C/kg, 0.206 C/kg, and 0.31 C/kg), A2 phospholipase and short-chain fatty acids that are indicative of an essential contribution of a membrane lipid component to the effect of radiation on Na-K pump of the neuron and the universality of the mechanisms of action of ionizing radiation on organisms differing in radiosensitivity.

[Effect of x-rays on the pacemaker neurons of Helix pomatia]. / Deistvie rentgenovskogo izlucheniia na ritmovodiashchie neirony vinogradnoi ulitki.

The effect of superlethal doses of ionizing radiation on exciting and electrical properties of giant neurons of the central nervous system of Helix pomatia has been investigated. At early times following irradiation the excitability does not significantly change whereas the membrane potential, resistance and pump-induced hyperpolarization increase. At later times, a stabilization of these parameters is followed by a diminution of resistance, a decrease of membrane potential and pump-induced hyperpolarization, and even the neuron death.

[Effect of ionizing radiation on the functional state of Helix pomatia neurons. Glucose metabolism and ATP levels]. / Deistvie ioniziruiushchei radiatsii na funktsional'noe sostoianie neironov vinogradnoi ulitki. Obmen gliukozy i uroven' ATF.

The ATP level in nerve ganglia of Helix pomatia was shown to decrease 15 and 30 min, and 1 and 3 h following irradiation (5.16 C/kg). The decrease was maximum in 60 min. The absorption and utilization of glucose via a pentose-phosphate route and in the Krebs cycle did not substantially change. It is concluded that the energy supply of nerve cells under study is not responsible for the decrease in the ATP level.

[Effect of ionizing radiation on the functional state of Helix pomatia neurons. The systems of Na+ and K+ transport]. / Deistvie ioniziruiushchei radiatsii na funktsional'noe sostoianie neironov vinogradnoi ulitki. Sistemy transporta Na+ i K+.

The influence of ionizing radiation (5.16 C/kg) on passive and active Na+ and K+ transfer within the giant neurons of edible snail (Helix pomatia) has been investigated. It has been shown that ionizing radiation increases passive permeability of membranes, inhibits active ion transport, changes the number and the affinity of functionally active Na+,K+-ATPase molecules. The authors discuss the mechanisms of action of ionizing radiation.

[Postradiation changes in the systems of active ion transport in the CNS. Na,K-ATPase]. / Postradiatsionnye izmeneniia sistem aktivnogo transporta ionov v TsNS. Na,K-ATFaza.

A study was made of the effects of irradiation with lethal (0.31 C/kg) and superlethal (12.9 C/kg) doses on Na,K-ATPase activity of various membrane formations in rat brain cortex. The results obtained indicated a significant increase in the activity of the enzyme at different times after irradiation.

[Effect of ionizing radiation on the functional state of snail neurons. Phospholipid composition and levels of free fatty acids]. / Deistvie ioniziruiushchei radiatsii na funktsional'noe sostoianie neironov vinogradnoi ulitki. Fosfolipidnyi sostav i uroven' svobodnykh zhirnykh kislot.

A study was made of the effect of ionizing radiation on the phospholipid composition and the level of free fatty acids in nervous ganglia of edible snails (Helix pomatia). Ionizing radiation was shown to decrease the total content of phospholipids and to change certain fractions and accumulation of lysoforms. The increase in the free fatty acid content indicated an activation of endogenous phospholipase hydrolysis. Model experiments on treatment of nervous ganglia with phospholipase A2 demonstrated a similarity of radiation-induced changes in the phospholipid content.

[Effect of ionizing radiation on the functional state of snail neurons. Cyclic nucleotide levels and phosphorylation of membrane proteins]. / Deistvie ioniziruiushchei radiatsii na funktsional'noe sostoianie neironov vinogradnoi ulitki. Soderzhanie tsiklicheskikh nukleotidov i fosforilirovanie membrannykh belkov.

A study was made of the effect of ionizing radiation, phospholipase A2, and low concentrations of mediators (for instance, acetylcholine and gamma-aminobutyric acid) on the content of cyclic nucleotides and phosphorylation of membrane proteins of Helix pomatia nervous ganglia. Ionizing radiation was shown to decrease considerably the levels of cAMP and cGMP which correlated with the diminution of membrane phosphorylation. Phospholipase A2 and low doses of mediators produced a modifying effect on the cyclic nucleotide content.

[Glycyl-glycine dipeptidase from cat nervous tissue]. / Glitsilglitsin-dipeptidaza nervnoi tkani koshek.

The local distribution of glycyl-glycine dipeptidase (EC 3.4.13.1) from cat nervous tissue was studied. Using disc-electrophoresis, the multiplicity of the enzyme molecular forms was demonstrated. Glycyl-glycine dipeptidase from water extract and the partially purified enzyme forms revealed three similar or identical values of the pH optimum. The curves for the dependence of the reaction rate versus substrate concentrations for all the three enzyme forms under study are S-shaped. The kinetic data and the values of the Hill coefficient calculated by different methods are suggestive of allosteric properties of the cat brain enzyme.