The use of 1H-NMR spectroscopy and refractometry for investigation of the distribution of nonelectrolytes of N-alcohol series between human red blood cells and extracellular medium.

Comparative analysis of 1H NMR spectroscopy and refractometry with respect to their application for investigating the distribution of nonelectrolytes of n-alcohol series (ethanol, 1,2-propanediol, glycerol) and polyethylene glycols (PEGs) with molecular masses of 400, 600, 1500 between human erythrocytes and extracellular medium was performed. The distribution coefficients (Q) for solutions of ethanol, 1,2-propanediol, glycerol, PEG-400, PEG-600 and PEG-1500 were obtained. The Q values decreased with the increase in the nonelectrolyte molecular mass from 1.23+/-0.12 for ethanol to 0.40+/-0.08 for PEG-1500 (1H NMR spectroscopy) and from 2.6+/-0.12 for ethanol to 0.23+/-0.03 for PEG-1500 (refractometry). It was shown that 1H-NMR high-resolution spectroscopy ensures more precise determination of Q values for nonelectrolytes with low molecular masses; for PEGs with high molecular masses, the accuracy of Q value calculation by this method was about 20%. On the contrary, refractometry can be used for investigating substances with high molecular masses; the error of Q value determination for solution of low-refractive substances, such as ethanol, may be more than 50%.

[Functional status of cryopreserved rat liver mitochondria]. / Izuchenie funktsional'nogo sostoianiia kriokonservirovannykh mitokhondrii pecheni krysy.

Mitochondria from the rat liver have been frozen down to -196 degrees C under protection of dimethylsulfoxide, after which they were subjected to periodical increase and decrease in temperature (cycling) in the ranges of -105 degrees C to -196 degrees C or -135 degrees to -196 degrees C. There have been observed some non-lethal damages of mitochondria which were revealed in the decrease in the respiratory control and in the ADP/O ratio after the cycling. The damage rate increased with the increase of the number of temperature decrease-increase cycles. The damages were also greater in the case when the upper limit of cycling temperature was higher than the glass transition temperature of the freezing medium (Tg = -126 degrees C). The non-lethal damages of mitochondria are explained by the influence of electric fields, appearing in the frozen sample during the temperature increase or decrease.

[Anomalous dependence of erythrocyte cytosol microviscosity on temperature and composition of the media]. / Ob anomal'noi zavisimosti mikroviazkosti tsitozolia éritrotistov ot temperatury i sostava sredy.

Abnormal decrease in microviscosity in erythrocytes cytosol during temperature decrease has been established when erythrocytes are in hypertonic sodium chloride solution in the presence of 1,2-propane diol and without it and also in the solution of polyethylene glycol-1500.

[The effect of temperature and concentrations of various substances on the microviscosity of erythrocyte cytosol]. / Vliianie temperatury i kontsentratsii razlichnykh veshchestv na mikroviazkost' tsitozolia éritrotsitov.

EPR spin-probe method was used to investigate the dependence of erythrocyte cytosol microviscosity (ECM) on the concentration of different substances and temperature. The critical ECM value has been determined after reaching of which erythrocytes become destroyed. It is shown that this ECM value is reached at different NaCl concentrations depending on the temperature.

[Structural and functional characterization of cytochrome oxidase encapsulated in liposomes in sodium chloride solutions]. / Strukturno-funktsional'nye kharakteristiki tsitokhromoksidazy, vstroennoi v liposomy v rastvorakh khlorida natriia.

The effect of NaCl concentration (0-2 M) on the absorption spectrum and enzymic activity of cytochrome oxidase built in lecithin liposome has been studied at 24 and 8 degrees C. It is shown that at 0,8 M NaCl concentration a conformational transition occurs that leads to the enzyme inactivation. The relationship between protein conformation and liposome state has been established.

[Study of the effect of low temperatures and organic solvents on the structure of model membranes using fluorescent probes]. / Issledovanie vliianiia nizkikh temperatur i organicheskikh rastvoritelei na strukturu model'nykh membran metodom fluorestsentnykh zondov.

By means of the fluorescence probes pyrene, DSP-12 and n-terphenyl the effect of low temperature, glycerol and 1,2-propylene glycol on the structure of lecithin liposomes and proteoliposomes formed by lecithin and cytochrome P-450 has been studied. Freezing-thawing and cryoprotectants were shown to modify surface area and internal volume of the lipid bilayer.

[Erythrocyte membrane permeability of Citellus undulatus during hibernation]. / Pronitsaemost' membran éritrotsitov Citellus undulatus v usloviiakh gipotermicheskogo khraneniia.

We have studied the influence of the erythrocyte hypothermic storage of long-tailed ground squirrels at various physiological states and white mongrel rats on the impairment of the barrier function of their membranes for ferricyanide. The membranes of sleeping and awakening ground squirrels demonstrate the highest stability (the structural integrity is sustained for 3-3,5 months), meanwhile rat blood erythrocytes maintain the barrier function only for 2 weeks. Beside structural and viscous changes in the erythrocyte membrane and the cytosol of hibernating ground squirrel an important role in maintaining barrier function under conditions of hypothermic storage is played by the content of animal blood plasma. Appearance of a non-typical EPR spin probe spectrum in some ground squirrel blood samples in non-equilibrium state of entering or arousing from hibernation has been observed.

[Study of erythrocyte dehydration using spin labels]. / Issledovanie degidratatsii éritrotsitov metodom spinovogo zonda.

Possibility of studying erythrocyte dehydration by ESR-spin probe is substantiated. Dehydration of erythrocytes in relation to osmolarity of sodium chloride solutions is investigated. The results are shown to agree with the data obtained by radioisotope method.

[Effect of elevated concentrations of sodium chloride and temperature on the state of erythrocyte cytosol]. / Vliianie povyshennykh kontsentratsii khlorida natriia i temperatury na sostoianie tsitozolia éritrotsitov.

It was shown by means of ESR-spin probe method that microviscosity of erythrocyte cytosol had a limiting value which could be reached by various concentrations of sodium chloride depending on temperature. With a temperature decrease when reaching this value haemolysis occurs.

[Effect of freezing and thawing on the structure and function of cytochrome oxidase]. / Vliianie zamorazhivaniia-otogreva na strukturu i funktsiiu tsitokhromoksidazy.

The effect of freezing-thawing on cytochrome oxidase from cattle heart was studied. The enzyme was characterized for its activity, absorption spectra, temperature perturbation differential spectra and conformational transitions. A decrease in the activity and conformational changes depend on the composition of the buffer system and the presence of potassium and sodium chlorides in the solution.

[Possibility of controlling orthostatic instability in spinal cord injuries]. / Vozmozhnosti bor'by s ortostaticheskoi neustoichivost'iu pri povrezhdeniiakh spinnogo mozga.

Hemodynamics were studied in 10 patients with high (cervical) spinal cord injury in a change to a vertical position. They were fitted with special antioverexertion gear (AOG) consisting of an abdominal, two thigh, and two knee inflatable rubber cuffs in which pressure of +50 mm Hg was produced. Measurements were taken every minute of arterial pressure, volumetric rate of blood flow in the upper limb (by venous-occlusion plethysmography), cardiac output and stroke volume (by body integral rheography); peripheral resistance and vascular resistance were calculated from a formula. Change of the patient to a vertical position without the use of the AOG was attended by a sharp fall in arterial pressure, stroke volume, and peripheral resistance and by marked tachycardia. Orthostatic collapse developed in the third-fourth minute. The use of the AOG prevented such a fall in the hemodynamic parameters which stayed on a higher level, this made it possible for the patients to remain in an erect position for 10 minutes and longer. These of the AOG in recommended in the first stage of training patients with sharply pronounced orthostatic instability.

[Study of the state of mitochondria at low temperatures by the ESR method]. / Issledovanie sostoianiia mitokhondrii pri nizkikh temperaturakh metodom EPR.

Possible usage of ESR probe method for studying low temperature effect on structural and functional state of mitochondria is under study. It is shown that during freezing out of mitochondrial water there is sharp dehydration of intermitochondrial matrix and membrane thickening. The facts are given about damage of barrier function of the membrane at the moment of appearance of extramitochondrial liquid phase during thawing.

[Hemodynamic changes during the orthostatic test in patients with spinal cord damage at different levels]. / Izmeneniia gemodinamiki pri ortostaticheskoi probe u bol'nykh s razlichnym urovnem povrezhdeniia spinnogo mozga.

Hemodynamics were studied during orthostatic load on a special orthotable in 54 patients with different levels of spinal cord interruption. With the patient in a horizontal and then in a vertical position, the arterial pressure, pulse, volume rate of blood flow in the forearm, and the cardiac output were recorded every minute. The total resistance of the vessels was calculated. Absence of constrictor reactions in the lower half of the trunk was revealed in patients with a high level of spinal cord damage, due to whicorthostatic collapse developed within the first minutes after they had been placed in a vertical posture. The orthostatic stability of such patients may be somewhat improved by producing additional external pressure to the lower part of the trunk (with special suits) and by means of other forms of special training. Patients with the spinal cord damaged at a low level (below the sixth thoracic vertebra) tolerate a 10-minute orthostatic load quite satisfactorily.