Vol 62, No 4 (2017)

Dinitrosyl iron complexes (DNICs) with thiol-containing ligands occur in animal tissues as paramagnetic (EPR-active) mononuclear and diamagnetic (EPR-silent) binuclear species with the presence of nitric oxide. They provide stabilization and storage (within protein-bound DNICs) of nitric oxide, as well as its transport (within low-molecular-weight DNICs) to biological targets to serve as donors of not only nitric oxide itself but also of the nitrosonium ion (NO⁺). The latter function determines the ability of DNICs to S-nitrosylate various thiol-containing proteins. In this way, the complexes participate in a wide range of physiological and biochemical processes. With respect to the high and diverse level of biological activity and dose dependence of DNICs, they mimic the endogenous nitric oxide system. Taken together with the broad occurrence of DNICs (predominantly in the diamagnetic form) in animal tissues, this fact points to their role as an “operating form” of nitric oxide. It is thought that drugs designed on the basis of DNICs can substantially improve the efficiency of modern medical practice.

The temperature trends of the standard thermodynamic functions of the native and denatured protein in solution are considered within the concept of excess mixing functions. It is assumed that some protein molecules adopt an intermediate state between native and denatured forms within the temperature range between cold and thermal denaturation and form metastable microphases as a result of a specific interaction with water. A phase diagram in the temperature–standard entropy coordinate plane representing an isobar family is proposed. Two limiting isobars are characterized by an entropy jump, which reflects the first-order phase transition between the native and denatured states. The isobars in the intermediate temperature range are represented as van der Waals curves, which reflect the equilibrium between the main phase of the molecules in native state and microphases. The difference between the phases disappears at critical points. It is assumed that the supercritical range is a macroscopically homogeneous single phase zone of reduced stability, which is represented by a dynamic system of monomers and oligomers of the native protein, monomers and clusters of the protein with partially unfolded structure. The phase diagram is collated with the elliptic phase diagram in the temperature–osmotic pressure plane.

A new model system has been developed to study the influence of reactive oxygen species on isolated mammalian cells in conjunction with the comet assay. The glucose-glucose oxidase system was used as a hydrogen peroxide generating source. The level of DNA damage was assessed in the splenocytes and the cells of bone marrow of mouse and in human leukocytes both in untreated cells and in cells treated with hydrogen peroxide generated by glucose oxidase using the alkaline comet assay in vitro. Various options for the location of the enzyme in the slides have been studied: in the layer with the cells, in the layer above the cells, or in solution on the surface of the slides. The option where glucose oxidase was in the upper layer of 0.5% agarose over the layer of the cells was optimal. It provided separation of the enzyme from the cells and avoided obstruction to the hydrogen peroxide exposure. For the whole blood study, the content of endogenous glucose must be taken into account. This approach can be used to study the level of DNA damage induced in vitro and for the detection of DNA repair, thereby expanding the possibilities of the method, while the experiments are conducted under controlled conditions.

Antioxidants suppress the formation of radicals in peroxidase processes. The chemiluminescence kinetic curves in the horseradish peroxidase/luminol/H₂O₂ system have been compared with those obtained from the mathematical model of the reaction. It was shown that the effect of trolox, ascorbate, and mexidol is a result of the reaction of the luminol radical with the inhibitor molecule (rate constants, 1.0·10¹⁰, 9.0·10⁹, and 2.3·10⁵ mol^–1 min^–1, respectively). The antiradical action of quercetin has been described by eight reactions that were based on the assumption of two reaction centers in the molecule, each reacting with two radicals. The hypothesis that the antioxidant molecule captures the enzyme intermediate radicals in peroxidase cycle, rather than the radical of the reaction product was not confirmed because the calculated curves differed from the experimental point positions. Apparently, the formation of radicals in the presence of peroxidases in living cells and the subsequent events, such as apoptosis, may be prevented not only by the inhibition of an enzyme but also by antioxidants that capture free-radical reaction products

A comparative study of the effects of the active pharmaceutical ingredients of amixin, aspirin, metronidazole, phenibut, and fenspiride, as well as corresponding pharmaceuticals on lipid membranes was carried out. Lipid membranes of L-α-dipalmitoylphosphatidylcholine and native carp spermatozoa were used as models. A decrease in the melting temperature of L-α-dipalmitoylphosphatidylcholine membranes in the presence of all active ingredients and pharmaceuticals was found using differential scanning calorimetry. The only exception was the group of phenibut, where a splitting of the melting peak was observed. It was found that in the pharmaceuticals studied the active pharmaceutical ingredients exhibit a determinative membranotropic effect, whereas excipients play a modulating role. Changes in the parameters of water ν_ОН bands in the L-α-dipalmitoylphosphatidylcholine membranes containing active pharmaceutical ingredients were quantitatively characterized by Fourier transform infrared spectroscopy. According to these parameters, the effect of the phenibut group differed in these parameters from that of the other ingredients. The changes of ν_ОН bands caused by excipients were elucidated. An increase in the permeability of carp sperm cell membranes to water was observed in vitro for pharmaceuticals that induced a decrease in the phase transition temperature of a model membrane (amixin) and lipid lateral phase separation (phenibut).

A comparative study of the effects of natural compounds with different biological activity spectra and mechanisms of action on the dynamics of the change in the redox-status of tumor and immune cells was carried out by measuring the intracellular level of reactive oxygen species depending on the dose and incubation time. The quinazoline alkaloid tryptanthrin, phenol propanoid rosmarinic acid, and the anticancer agent doxorubicin were tested. This study was performed on Ehrlich adenocarcinoma tumor cells and splenocytes after loading with the oxidant sensing fluorescent probe 2′,7′-dichlorofluorescein diacetate. It was shown that when rosmarinic acid influences tumor cells it has a pronounced antioxidant activity at a low dose (1 mg/mL), while a high dose of rosmarinic acid (10 mg/mL) exhibits prooxidant activity. Interestingly, in a splenocyte cell culture, rosmarinic acid reduced the level of reactive oxygen species at low and high doses. The combined application of doxorubicin with rosmarinic acid at a low dose reduced the prooxidant effect of doxorubicin, which is a potent inducer of reactive oxygen species in tumor cells. Tryptanthrin is also a potent inducer of reactive oxygen species with respect to tumor and immune cells; it is a more potent prooxidant than doxorubicin. In addition, tryptanthrin enhanced the doxorubicin-induced formation of reactive oxygen species by tumor cells in the combined use of doxorubicin with tryptanthrin. However, the prooxidant effect of tryptanthrin is short-term and decreases after a prolonged incubation. The effect of reactive oxygen species on the potent mechanisms of the biological activities of the individual and combined substances under study is discussed.

The behavior of blood cells of different animal species in an ultrasonic field was investigated. The ranges of modulation frequencies that caused irreversible changes were revealed. The following cytomorphological effects of ultrasound (a carrier frequency of 880 kHz and 2.64 MHz, a modulation range from 10 to 1000 Hz) on red blood cells were detected: a change in the shape, the formation of symmetric groups around the cell and chains of red blood cell without cytolysis, and the occurrence of ghost cells. Changes in the leukograms did not always depend on the animal species under an equal-energy impact. White blood cells changed before red blood cells, 12–20 s after insonation at active frequencies. The effect on granulocytes, which led to the damage of the cytoplasmic membrane and then of the whole cell, was observed earlier than that on agranulocytes. In small lymphocytes degenerative changes were recorded significantly later, after 50–90 s. All the animal species had similar effects within an intensity range of 0.2–0.7 W/cm² and at modulation frequency of 10–100 Hz: leukopenia, cytolysis, destruction and aggregation of cells, foaming of the cytoplasm of granulocytes, rupture of the cytoplasmic membrane, bursting of nuclei (general), their deformation, and disturbance of their borders.

The objective of this work was to study how a prolonged course of inhalations of nitric oxide or singlet oxygen modify crystallization of the blood serum in rats. Experiments were performed with 50 adult Wistar rats, which were divided into five equal groups. The control group (n = 10) included intact rats, which were not exposed to any manipulation other than a single blood drawing. Rats of groups 2, 3, and 4 received inhalations of nitric oxide at 20, 50, and 100 ppm, respectively, daily for 30 days. Group 5 rats (n = 10) received a similar course of inhalations of singlet oxygen for 30 days. Blood samples were drawn from the sublingual vein in rats of the test groups immediately after completion of the inhalation course (day 30 of the experiment) and in the recovery period (day 60 of the experiment) and tested for crystallogenic activity. Dried samples were evaluated visually for crystallizability, structure index, facia destruction degree, and marginal zone clarity, using respective scales. A prolonged course of NO inhalations was found to modulate the crystallogenic properties of the rat serum. An optimal response was recorded at the lowest nitric oxide concentration (20 ppm). Higher NO concentrations caused more adverse changes in serum crystallization after the end of the inhalation course and hindered the recovery processes. Singlet oxygen inhalations for 30 days did not exert a considerable adverse effect on the crystallogenic properties of the rat serum.

The hypothesis is proposed that an external local stimulus may cause a change in the phase relationships of oscillations in the peripheral skin blood flow of contralateral extremities. To test this assumption, the wavelet phase coherence of skin blood flow oscillations of the left and right forearms of 18 healthy volunteers of both sexes at rest and in response to unilateral local heating was investigated. An area of the skin of the left forearm was exposed to heat and the native blood perfusion in an area of the skin of the right forearm was recorded simultaneously. It was shown that an asymmetric local change of skin perfusion led to a significant change in the phase relationships of the blood flow oscillations in all the analyzed frequency ranges. A significant reduction of phase synchronization of oscillations of skin blood flow in the range of endothelial, neurogenic, and myogenic activity, as well as in the range of respiratory rhythm was revealed. In contrast, in the range of the cardiac rhythm, a significant increase in phase synchronization of the oscillations of the blood flow of contralateral skin areas of the forearm was detected.

The results of optical spectral studies in the wavelength range of 250–1500 nm and frequencies of 6000–400 cm^–1 of samples of bile and pancreatic juice with the development of malignancy in the tissues of the pancreas are presented. It was shown that the development of degenerative processes in the studied biological fluids led to an increase in the intensity of the spectral profile of absorption at low frequencies (1600–400 cm^–1) and the appearance of a peak near the frequency of 840 ± 5 cm^–1 formed by the vibrations of the O–O groups of aliphatic and aromatic peroxides or peroxide acids. It was demonstrated that the development of malignant processes led to an increase and to a decrease of the density and size of particles in the samples of bile and pancreatic juice, respectively, as inferred from the corresponding increase and decrease of the coefficients of absorption and scattering of light.

A mass spectrometer with capillary and membrane interfaces was used during anesthesia to deliver the gas mixture from the breathing circuit of the inhalation anesthesia machine (IAM) into the ionic source of an analyzer and to measure the concentration of CO₂ released from the skin in real time. The extent of the stress response during surgery correlated with the time course of changes in the concentrations of CO₂ released from the lungs and skin. The CO₂ concentration and the BIS index of changes in EEG frequency spectrum were measured simultaneously during intravenous total propofol–fentanyl anesthesia. The BIS index and the concentrations of CO₂ released from the lungs and skin were found to correlate with the most traumatic steps of the surgical procedure.

The patterns of the phase portraits of vegetation (agrophytocenosis, woody vegetation) constructed using two-dimensional space radiation temperature values and Normalized Difference Vegetation Index were studied. An analysis of the phenological variability of vegetation in the south of the Krasnoyarsk Territory and the Republic of Khakassia during the growing seasons of 2003 and 2006 was carried out. Distinctive features of the phase portraits of agrophytocenosis and woody vegetation were revealed. The possibility of determining the boundaries of phenological states in the phytocenosis, and the transition range from one state into another was shown. Based on the complex analysis of the reflexive and radiative properties of the plant samples, an algorithm for calculating the start and end of the growing season was developed.

A study was made of the effects that 6- and 12-h shifts in diurnal geomagnetic variation relative to the night–day light cycles exert on roach Ritulus ritulus L. embryos. Either temporal shift in diurnal geomagnetic variation stimulated blastomere proliferation and early prelarval hatching in exposed embryos compared to controls. Underyearlings developing from exposed embryos displayed higher locomotor activity in a plusshaped maze, a lower number of rays in the anal fin, a redistribution of vertebrae through sections of the vertebral column, and a higher number of seismosensory system openings in the mandibular and preopercular bones. The effects were similar to those described previously for roaches exposed to a simulated geomagnetic storm during embryonic development. The results support the hypothesis that animals perceive geomagnetic storms as a dramatic disturbance that occurs in the habitual diurnal geomagnetic variation at an unusual time relative to the night–day light cycle, which acts as a primary zeitgeber of circadian biological rhythms.