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Having two cases of extensive resection of the small intestine, we consider it necessary to highlight these cases on the pages of the press.

Ommochromes are screening and antioxidant pigments in the compound eyes of invertebrates and fulfil the functions of light filtration, light absorption, and antioxidant defense. We report here the first observation that ommochromes display antiglycation activity in vitro. Ommochromes were prepared from the eyes of insects of three different families: Strationyidae, Sphingidae, and Acrididae. All the ommochromes studied were found to inhibit the reaction forming fluorescent serum albumin modification products in the presence of high fructose concentrations (fructosylation). Ommochromes from the eyes of the black soldier fly (Hermetia illucens) were the most effective fructosylation inhibitors. Ommochromes oxidized with hydrogen peroxide produced no inhibitory action in relation to glycation. Our results are of interest both for understanding the biological role of ommochromes in invertebrates, in particular for clarifying their influence on oxidative modification of the proteins of the retinular and pigment cells of ommatidia, and for using them to create pharmacological agents for the treatment and prevention of pathology associated with the development of metabolic syndrome.

Lipofuscin granules (LGs) are accumulated in the retinal pigment epithelium (RPE) cells. The progressive LG accumulation can somehow lead to pathology and accelerate the aging process. The review examines composition, spectral properties and photoactivity of LGs isolated from the human cadaver eyes. By use of atomic force microscopy and near-field microscopy, we have revealed the fluorescent heterogeneity of LGs. We have discovered the generation of reactive oxygen species by LGs, and found that LGs and melanolipofuscin granules are capable of photoinduced oxidation of lipids. It was shown that A2E, as the main fluorophore (bisretinoid) of LGs, is much less active as an oxidation photosensitizer than other fluorophores (bisretinoids) of LGs. Photooxidized products of bisretinoids pose a much greater danger to the cell than non-oxidized one. Our studies of the fluorescent properties of LGs and their fluorophores (bisretinoids) showed for the first time that their spectral characteristics change (shift to the short-wavelength region) in pathology and after exposure to ionizing radiation. By recording the fluorescence spectra and fluorescence decay kinetics of oxidized products of LG fluorophores, it is possible to improve the methods of early diagnosis of degenerative diseases. Lipofuscin ("aging pigment") is not an inert "slag". The photoactivity of LGs can pose a significant danger to the RPE cells. Fluorescence characteristics of LGs are a tool to detect early stages of degeneration in the retina and RPE.

Abstract The review considers the spectral kinetic data obtained by us by femtosecond absorption laser spectroscopy for the photochromic reaction of retinal isomerization in animal rhodopsin (type II), namely, bovine visual rhodopsin and microbial rhodopsins (type I), such as Exiguobacterium sibiricum rhodopsin and Halobacterium salinarum bacteriorhodopsin. It is shown that the elementary act of the photoreaction of retinal isomerization in type I and type II rhodopsins can be interpreted as a transition through a conical intersection with retention of the coherence of the vibrational wave packets generated during excitation. The coherent nature of the reaction is most pronounced in visual rhodopsin as a result of the barrier-free movement along the excited surface of potential energy, which also leads to an extremely high rate of retinal isomerization compared to microbial rhodopsins. Differences in the dynamics of photochemical reactions of type I and type II rhodopsins can be related to both differences in the initial isomeric forms of their chromophores (all-trans and 11-cis retinal, respectively), as well as with the effect of the protein environment on the chromophore. Despite the practically identical values of the quantum yields of the direct photoreaction of visual rhodopsin and bacteriorhodopsin, the reverse photoreaction of visual rhodopsin is much less effective (φ = 0.15) than in the case of bacteriorhodopsin (φ = 0.81). It can be assumed that the photobiological mechanism for converting light into an information process in the evolutionarily younger visual rhodopsins (type II rhodopsins) should be more reliable than the mechanism for converting light into a photoenergetic process in the evolutionarily more ancient microbial rhodopsins (type I rhodopsins). The low value of the quantum yield of the reverse reaction of visual rhodopsin can be considered as an increase in the reliability of the forward reaction, which triggers the process of phototransduction.

C. Clinical guideline is the result of an agreed decision of experts, adopted on the basis of a thorough analysis of literature data, as well as recommendations of foreign guideline GINA: Global Strategy For Asthma Management And Prevention. Updated 2019. The document provides an updated definition of bronchial asthma (BA), gives new approaches to the classification and diagnosis of the disease, proposes modern treatment regimens based on the results of multicenter international clinical trials, which justifies the high evidence for such therapeutic tactics. New principles for the distribution of patients to phenotypes, which should be taken into account when choosing treatment regimens, are presented, algorithms for initial and maintenance therapy, and new approaches to the treatment of exacerbations of the disease are presented. In previous publications of the manual (Asthma and Allergy, 2020, № 2, № 3), an updated definition and pathogenetic mechanisms of BA were presented, new approaches to the classification and diagnosis of the disease were outlined, and the definition and assessment of asthma control were given. The principles of assessing the severity of asthma, as well as the difference between severe and uncontrolled asthma are considered. Standards for the treatment of asthma patients according symptoms control and minimize risk are presented. The basic principles of asthma management and alternative correction strategies of treatment are considered. The third part of the manual presents a stepwise approach to the correction of therapy, immunotherapy with allergens, vaccination, indications for referral to a specialist consultation. The guideline is addressed to doctors at all levels of medical care – family doctors, general practitioners, pulmonologists, allergists, cardiologists, rehabilitologists. Key words: bronchial asthma, pathogenesis, classification, diagnosis, therapy

This paper considers the role of the Academy of Sciences in the formation and development of space physiology. Academicians M.V. Keldysh, N.M. Sisakian, L.A. Orbeli, V.N. Chernigovsky, A.V. Lebedinsky, V.V. Parin, O.G. Gazenko, A.I. Grigoryev, and other famous Russian scientists made a significant contribution to research in the field of space life sciences. Their active participation in studies allowed manned spaceflights to be carried out. The accumulated experience of traditional physiology made it possible to solve the fundamental problems of new scientific areas related to the presence of man in space. The Institute of Biomedical Problems, which in its activities has always relied on cooperation with many institutes of the Academy of Sciences, has made a significant contribution to the development of space physiology and related sciences, which made our country one of the leaders in manned astronautics.

The small heat shock protein α-crystallin is a main protein in the lens of the eye. It supports lens transparency by blocking the aggregation of damaged proteins in the cytoplasm of lens fiber cells. Using detergent-induced protein denaturation, it was shown that α-crystallin supports the refolding of denatured proteins. The aim of this paper was to study the ability of α-crystallin to restore the native structure of the physiologically relevant substrate of UV-damaged βL-crystallin. It was shown α-crystallin brakes the aggregation of UV-damaged βL-crystallin at conditions close to physiological (temperature, pH, solvent ionic strength). Full blocking of aggregation was obtained at a 5/1 ratio of α-crystallin and the target protein (mol/mol). DSC study has shown that denaturation temperatures of native, UV-damaged βL-crystallin and UV-damaged βL-crystallin incubated with α-crystallin for 24 h were not different and were equally of 64.0 ± 0.3°C. The total energy of the denaturation of stable water-soluble forms of UVβL-crystallin did not differ from the denaturation energy of UVβL-crystallin incubated with α-crystallin for 24 h. These results directly indicate that the interaction of denatured UVβL-crystallin and α-crystallin does not lead to the refolding of denatured protein.

α-Crystallin maintains the transparency of the lens by preventing the aggregation of damaged proteins. The aim of our work was to study the chaperone-like activity of native α-crystallin in near physiological conditions (temperature, ionic power, pH) using UV-damaged βL-crystallin as the target protein. α-Crystallin in concentration depended manner inhibits the aggregation of UV-damaged βL-crystallin. DSC investigation has shown that refolding of denatured UV-damaged βL-crystallin was not observed under incubation with α-crystallin. α-Crystallin and UV-damaged βL-crystallin form dynamic complexes with masses from 75 to several thousand kDa. The content of UV-damaged βL-crystallin in such complexes increases with the mass of the complex. Complexes containing >10% of UV-damaged βL-crystallin are prone to precipitation whereas those containing

For the purpose of optogenetic prosthetics of the receptive field of the retinal ganglion cell, we have created a bicistronic genetic construct that carries genes of excitatory (channelorhodopsin2) and inhibitory (anionic channelorhodopsin) rhodopsins. A distinctive feature of this construct is the combination of two genes into one construct with the mutant IRES inserted between them, which ensures precise ratio of the expression levels of the first and second gene in each transfected cell. It was found that the illumination of the central part of transfected neuron with light with a wavelength of 470 nm causes the generation of action potentials in the cell. At the same time, light stimulation of the periphery of the neuron causes cessation of the generation of action potentials. Thus, we were able to simulate the ON-OFF interaction of the receptive field of the retinal ganglion cell using optogenetic methods. Theoretically, this construction can be used for optogenetic prosthetics of degenerative retina in case of its delivery to ganglion cells using lentiviral vectors.

The review discusses the prospects of using rhodopsin as an optogenetic tool for prosthetics of degenerative (blind) eye retina and the principles of optogenetic techniques. Retinal-containing proteins that depolarize/hyperpolarize the plasma membrane of nerve cells and, accordingly, excite/inhibit physiological activity of neurons, are described. The problem of what cells of the degenerative retina can be treated with what particular rhodopsins is discussed in detail. Viruses and promoters required for the rhodopsin gene delivery into the degenerative retina cells are described. In conclusion, main concepts and tasks associated with the optogenetic prosthetic treatment of degenerative retina employing rhodopsins are presented.

A review of our own data and published material on the screening pigments of the eyes of vertebrates and invertebrates and the human eye, i.e., melanosomes and ommochromes, is presented. The role of these pigments in the vision of vertebrates and invertebrates as antioxidant organelles is considered, as is the role of melanosomes in the physiology, aging, and pathology of the human eye.

The authors discuss the main strategies for returning vision to blind people: electronic and optogenetic prosthetics of degenerative (blind) retina. Primary attention is paid to the prospects of retinal prosthetics for the blind using the methods of modern optogenetics. Photosensitive retinal-containing proteins, rhodopsins, are considered as tools for such prosthetics. The question of which particular cells of the degenerative retina and which rhodopsins can be prosthetic, as well as the ways of delivering the rhodopsin genes to these cells, is discussed. In conclusion, the main provisions and problems related to optogenetic prosthetics of degenerative retina are formulated.

Electricity consumption by people is increasing every year, followed by an increase in harmful emissions of carbon dioxide into the atmosphere during its generation. A promising solution to the problem of global pollution can be an oxy-fuel technology for energy production. It has been proven that the Allam cycle at an initial temperature of 1100 C is the most efficient oxy-fuel cycle. With a further increase in the initial temperature, the efficiency of this cycle decreases due to an increase in the relative coolant flow rate. This paper discusses the effect of the changeover from carbon dioxide to nitrogen coolant on thermal and hydraulic characteristics of cooling channels for the first-stage blade of a carbon dioxide turbine. We have found that, upon changeover from carbon dioxide to nitrogen cooling, the heat transfer coefficient decreases for a channel with pin intensifiers 1.3 to 1.65 times, for a channel with pin-and-dimple intensifiers, 1.65 to 1.77 times. We have also found that, upon changeover from pin intensifiers to pin-dimple ones, the heat transfer coefficient is increased for a cooling system using carbon dioxide coolant 2.2 to 2.5 times, whereas when using nitrogen coolant, the heat transfer coefficient remains unchanged. It has been also found that, to maintain a constant heat transfer coefficient upon changeover from carbon dioxide to nitrogen coolant, we should provide a 23.6% higher nitrogen flow rates compared to dioxide.

Single intraperitoneal injection of methylnitrosourea (MNU) induces in mice the loss of retinal photoreceptors as a nonlinear dose response (Tronov et al. 2015). DNA repair was the putative mechanism for causing a threshold of DNA alkylation in retina cells. Photoreceptor degeneration can stimulate Muller glial cells to transdifferentiate into photoreceptor-like cells in adult mouse retina treated with MNU (Wan et al., 2008). In this paper, we evaluated Muller cell proliferative response to different doses of MNU and compared the response to DNA damage and repair in suspensions of retinal and Muller cells using a comet assay and BrdU (thymidine analogue) as a marker of proliferation. MNU administration in the dose ≤ 40 mg/kg did not result in the activation of Muller cell proliferation in 3 days after the treatment. By this time point, no DNA damage after this dose was observed. For MNU doses that exceed 50 mg/kg, TUNEL-detected death of retinal photoreceptors increased more than 10-fold in the proliferating pool of Muller cells. DNA breaks (single- and double-strand breaks and AP sites) were observed. The results are discussed within the framework of the concept of misbalance of excision repair that results in formation of cytotoxic intermediates in DNA initiated death of photoreceptors followed by activation of Muller retinal cells.

The authors analyze their own and published data on the screening pigments of the eyes of vertebrates and invertebrates and the human eye, i.e., melanosomes and ommochromes. The structure, biochemistry, and functions of these pigments in the vision of vertebrates and invertebrates as light-filtering and light-absorbing organelles are discussed.

A quantum-classical model of cis-trans photoisomerization of the visual pigment rhodopsin chromophore was investigated in wide ranges of parameters. The quantum subsystem of the model includes three electronic states for rhodopsin: the ground state, the excited state, and the ground state of primary photoproduct. The local temperature of the mass points of the classical subsystem was used as a main reference quantity. The best agreement with experimental data was shown to be in the range of moderate temperatures in agreement with the Raman spectroscopy data. The essential role of a quick transfer of the photoexcitation excess energy into apoprotein part in photoproduct stabilization process was illustrated. Also, the fundamental nature and the local character of the photoreaction were shown in the numerical investigations.

A review of physicochemical properties, photochemistry, functions, and evolution of retinal-containing proteins (microbial and of metazoan rhodopsins, mostly visual rhodopsins) is provided. Comparative physiology of visual rhodopsins is considered in detail, mainly the molecular mechanisms of their spectral tuning.

For the first time, it was found that the hormone melatonin exhibited antiglycation activity in vitro. It was shown that melatonin significantly slowed down the accumulation of fluorescent Schiff adducts formed as a result of BSA modification in the presence of high concentration of fructose. It was noted that, unlike the fructosylation reaction, melatonin did not affect the process of modification of BSA by methylglyoxal. We assume that melatonin is able to inhibit the development of the Maillard reaction but does not affect the process of BSA modification by reactive carbonyls.

Optogenetics is a powerful technique in neuroscience that provided a great success in studying the brain functions during the last decade. Progress of optogenetics crucially depends on development of new molecular tools. Light-activated cation-conducting channelrhodopsin2 was widely used for excitation of cells since the emergence of optogenetics. In 2015 a family of natural light activated chloride channels GtACR was identified which appeared to be a very promising tool for using in optogenetics experiments as a cell silencer. Here we examined properties of GtACR2 channel expressed in the rat layer 2/3 pyramidal neurons by means of in utero electroporation. We have found that despite strong inhibition the light stimulation of GtACR2-positive neurons can surprisingly lead to generation of action potentials, presumably initiated in the axonal terminals. Thus, when using the GtACR2 in optogenetics experiments, its ability to induce action potentials should be taken into account. Our results also open an interesting possibility of using the GtACR2 both as cell silencer and cell activator in the same experiment varying the pattern of light stimulation.

The Pavlov Physiological Society, which will celebrate its centenary in 2017, has long enjoyed recognition among the scientific community and has always worked to consolidate the wide circle of specialists who are either directly or indirectly related to the study of physiological mechanisms. The current President of the society Academician M.A. Ostrovsky discusses the history of the creation of the Physiological Society, its goals and objectives, and its achievements and role in the development of Russian physiological science. He particularly emphasizes the significance of modern integrative physiology, which marks a new stage in the development of this science, opening broad horizons in understanding the mechanisms of the living organism and the phenomenon of life as a whole.

The fluorescence lifetimes of lipofuscin fluorophores contained in chloroform extracts from retinal pigment epithelium (RPE) of human cadaver eyes without signs of pathology were evaluated by single photon counting. The comparison of fluorescence lifetimes of N-retinylidene-N-retinylethanolamine (A2E) and its photooxidation and photodegradation products has been carried out. It was shown that the contribution of A2E to the total fluorescence of chloroform extract from lipofuscin granules is not major. The results are important for the improvement of noninvasive diagnostic method of degenerative diseases of the retina and RPE-fundus autofluorescence (FAF).

The concept of radiation risk to human interplanetary flights is proposed and substantiated. As opposed to traditional approaches, which associate radiation risk to crews mostly with late development of tumor processes in the organism, the notion successful mission outcome probability is introduced. The probability of radiation damage under these conditions is considered mainly as a result of the action of heavy nuclei of galactic cosmic rays on structures of the central nervous system, which may lead to changes in the higher integrative functions of the brain, causing degradation of operator performance.

α-Crystallin maintains the transparency of the lens by preventing the aggregation of damaged proteins. The aim of our work was to study the chaperone-like activity of native α-crystallin in near physiological conditions (temperature, ionic power, pH) using UV-damaged β

Anionic channelrhodopsin slow ChloC was expressed in the culture of nerve cells and in vivo in mouse brain. We demonstrated ability of slow ChloC to suppress effectively the activity of the neuron in response to the illumination with the visible light. It has been shown for a first time that slow ChloC works equally efficiently in both neuronal culture and in the whole brain being expressed in vivo. Thus, slow ChloC could be considered as an effective optogenetic tool capable in response to light stimulation to inhibit the generation of action potentials in the neuron.

The effect of continuous UV radiation and hydrogen peroxide on destruction and antioxidant properties of synthetic DOPA-melanin (prepared by oxidation of 3,4-dihydroxyphenylalanine (DOPA)) and melanosomes isolated from cells of the retinal pigment epithelium (RPE) was investigated. The kinetics of melanin destruction was recorded based on the accumulation of fluorescent low-molecular-weight reaction products, the antiradical activity of melanin was determined by chemiluminescence method, the concentration of free radical products was measured by electron paramagnetic resonance, and the antioxidant activity of melanins was estimated by their inhibitory effect on lipid peroxidation. It was shown that UVC—UVA irradiation (up to 5 hours) of DOPA-melanin and melanosomes of retinal pigment epithelium decreased neither the latency period of luminol chemiluminescence nor the inhibitory action of pigments on Fe2+- and UV-induced peroxidation of cardiolipin liposomes. However, very long UV irradiation gave rise to fluorescent destruction products, decreased the concentration of paramagnetic centers in the pigment (especially light-dependent ones), and decreased the antiradical and antioxidant activities. For example, UV irradiation of DOPA-melanin during 52 h resulted in approximately a 2-fold decrease in the concentration of paramagnetic centers and decline of antiradical and antioxidant activities. However, even with such a hard irradiation the pigment retained significant inhibitory activity against lipid peroxidation. The oxidative destruction of DOPA-melanin in the presence of hydrogen peroxide in the dark resulted in complete destruction of the polymer and loss of its protective properties. It is assumed that destruction of RPE cell melanin is caused mainly by oxidative processes.

Emerging body of data indicate protecting effect of low level of stress (preconditioning) on retina. Our previous study revealed non-linear dose-response relationship for cytotoxicity of both ionizing radiation and N-methyl-N-nitrosourea (MNU) on mouse retina. Moreover, non cytotoxic dose of MNU increased tolerance of retina to following challenge dose of MNU. This result displays protection of retina through mechanism of recovery. In present study we used the mouse model for MNU-induced retinal degeneration to evaluate adaptive response of retina to proton irradiation and implication in it of glial Muller cells. The data showed that the recovery of retina after genotoxic agents has been associated with increased efficacy of DNA damage repair and lowered death of retinal photoreceptor cells.

The effect of superoxide radicals on melanin destruction and degradation of melanosomes isolated from cells of retinal pigment epithelium (RPE) of the human eye was studied. We found that potassium superoxide causes destruction of melanin in melanosomes of human and bovine RPE, as well as destruction of melanin from the ink bag of squid, with the formation of fluorescent decay products having an emission maximum at 520-525 nm. The initial kinetics of the accumulation of the fluorescent decay products is linear. Superoxide radicals lead simultaneously to a decrease in the number of melanosomes and to a decrease in concentration of paramagnetic centers in them. Complete degradation of melanosomes leads to the formation of a transparent solution containing dissolved proteins and melanin degradation products that do not exhibit paramagnetic properties. To completely degrade one melanosome of human RPE, 650 ± 100 fmol of superoxide are sufficient. The concentration of paramagnetic centers in a melanolipofuscin granule of human RPE is on average 32.5 ± 10.4% (p < 0.05, 150 eyes) lower than in a melanosome, which indicates melanin undergoing a destruction process in these granules. RPE cells also contain intermediate granules that have an EPR signal with a lower intensity than that of melanolipofuscin granules, but higher than that of lipofuscin granules. This signal is due to the presence of residual melanin in these granules. Irradiation of a mixture of melanosomes with lipofuscin granules with blue light (450 nm), in contrast to irradiation of only melanosomes, results in the appearance of fluorescent melanin degradation products. We suggest that one of the main mechanisms of age-related decrease in melanin concentration in human RPE cells is its destruction in melanolipofuscin granules under the action of superoxide radicals formed during photoinduced oxygen reduction by lipofuscin fluorophores.

5-Hydroxybenzo[d]thiazol-2-ylammonium N-acetyl-l-cysteinate (oxibiol) was synthesized and studied. This novel water-soluble azaheterocyclic antioxidant is a white crystalline solid (m.p. 148–150 °C) soluble in ethanol and water. The UV spectrum of oxibiol shows two absorption bands at 220±1 and 265±1 nm. Its antiradical activity was examined using a homogeneous hydrophilic chemiluminescent system. The emission quenching constant of oxibiol is (2.4±0.4)·105 L mol−1, which is nearly seven times that of the antioxidant mexidol widely used in current medical practice. Oxibiol efficiently inhibits the free radical oxidation of photoreceptor cells that is induced by iron(II) ions and UV and visible light in the presence of photosensitizers. Oxibiol is especially effective in suppressing the photoinduced lipid peroxidation sensitized by lipofuscin granules from human retinal pigment epithelial cells. Oxibiol is highly resistant when exposed to UV light. Being a novel, more efficient and photoresistant antioxidant, oxibiol can also find other medical applications and replace the widely used agent mexidol.

This review describes published and original data concerning the evolution, structure, and spectral and photochemical properties of the visual pigment rhodopsin.

Retinopathy of animals is induced by many DNA-damaging agents. This fact shows that DNA lesions may initiate retinal degeneration. The aim of our work was to study the effects of gamma and proton irradiation and single administration of methylnitrosourea (MNU) on mice retina. We assessed morphological changes, DNA damage and repair, as well as expression of proteins (p53, ATM, PARP, FasR, and caspase 3) participating in apoptosis in retina. 14 Gy was the equitoxic dose for induction of DNA single-strand breaks by both gamma- and proton irradiation. However, protons were twice as effective as γ rays in induction of DNA double-strand breaks. All breaks have been repaired for ≤10 h. Irradiation resulted in increased expression of p53 and ATM. Seven days after irradiation, no signs of cell death and retinal degeneration were observed. Proton irradiation with 25 Gy resulted in destructive changes in retina localized mainly in the photoreceptor layer. These changes were accompanied by enhanced expression of proapoptotic proteins. A single systemic administration of MNU (70 mg/kg) increased intracellular levels of p53, PARP, FasR, and Caspase 3 followed by destructive changes in retina with sings of apoptosis in photoreceptors. Similarly to irradiation, a halved MNU dose did not exhibit a cytotoxic effect on retina. A high level of spontaneous DNA damage at apurine and apyrimidine sites were observed in mouse retina. The results show that there is a genotoxic threshold in initiation of retinal cell death in vivo. It is suggested that topoisomerase 2 translates primary DNA damage into a cytotoxic effect in retina.

The key physiological functions of the rhodopsin molecule are reviewed. Molecular mechanisms of visual pigments spectral tuning, photoisomerization of the 11-cis-retinal chromophore that triggers the phototransduction process, formation of physiologically active state of rhodopsin as a G-protein-coupled receptor, rhodopsin visual cycle, and consequences of its impairment are evaluated. Visual pigment rhodopsin performs several functions, providing spectral sensitivity of photoreceptor cells, phototransduction processes and light and dark adaptation. Genetically determined defects of visual pigment molecule and proteins involved into mechanisms of phototransduction and adaptation or into mechanism of visual cycle are directly linked to pathogenesis of different forms of degenerative retina diseases. Understanding the molecular mechanisms of these physiological processes uncovers the way to direct investigation of pathogenesis of these severe eye diseases.

The damaging effect of lipofuscin granules from the human retinal pigment epithelium and fluorophore A2E was studied on models of calcein- and ascorbate-loaded cardiolipin liposomes and outer segments of the bovine eye photoreceptor cells in dark and under visible light irradiation. In dark fluorophore A2E induces the release of calcein from calcein-loaded liposomes and reduces the lifetime of the artificial bilayer lipid membrane prepared from dioleyl phosphatidilcholine. A similar detergent-like action A2E exhibits towards ascorbate-loaded liposomes, significantly accelerating the release of ascorbate in dark. In the presence of A2E, irradiation with the full visible light (390–700 nm) stimulates both the release of ascorbate from liposomes and accelerates the destruction of the bilayer lipid membrane. Retinal pigment epithelium lipofuscin granules also accelerate the release of ascorbate from ascorbate-loaded liposomes under visible light irradiation; the blue light (457.9 nm) was twice as more efficient as the green light (514.5 nm). The preliminary irradiation of A2E with the visible light decreases its detergent-like action on the cardiolipin liposomal membranes under the dark conditions and the photosensitizing effect on the lipid peroxidation of the outer segments of photoreceptor cells. Unlike A2E, the visible light irradiation of a suspension of lipofuscin granules under similar conditions does not noticeably decrease their sensitizing activity towards lipid peroxidation. It is assumed that the phototoxicity of retinal pigment epithelium lipofuscin granules is related not only to A2E in their composition, but depends mainly on the content of other photosensitizers (chromophores) in the granules.

The structure of the oligomeric protein α-crystallin from bovine eye lens was investigated by small-angle neutron scattering (SANS) with contrast variation. Based on the SANS curves, the match point for α-crystallin (43% D2O) and its average scattering length density at this point (2.4·10(10) cm(-2)) were evaluated. The radius of gyration and the distance distribution functions for α-crystallin were calculated. On the basis of these calculations, it was concluded that α-crystallin is characterized by homogeneous distribution of scattering density in the domains inaccessible for water penetration, and all polypeptide subunits in α-crystallin oligomers undergo equal deuteration. The latter indicates that all α-crystallin subunits are equally accessible for water and presumably for some other low molecular weight substances. These conclusions on the α-crystallin structure (homogeneous distribution of scattering density and equal accessibility of all subunits for low molecular weight substances) should be taken into account when elaborating α-crystallin quaternary structure models.

Four randomized groups of male mice F1 (C57Black/CBA) were investigated: a) UV-irraidated (UV-A, 15 min daily during 9 months, dose 5.6 + 1.2 W/m2), b) gamma-rays irradiated (2 Gy), single, c) influence for combination of UV- and gamma-rays treatment, d) aging. The lens opacities were measured on 7th and 10th month. The expert method based on six grade scale was used for cataract measure. On 7th month the median of lens opacities were Aging group = 0; UV-irradiated group = 2.5; gamma-irradiated group = 4.75; gamma- and UV-irradiated group = 6.0. The difference between all groups was significant (p < 0.004, Kruskall-Wallis ANOVA test). The Conover post hock test has shown the significant difference for all comparison pairs (p < 0.002) with the exception of UV-irradiated group, gamma-irradiated group, gamma- and UV-irradiated group. On 10th month the lens opacities were strongly increased: Aging group = 2.5; UV-irradiated group = 5.0; gamma-irradiated group = 6.5; gamma- and UV-irradiated group = 7.5 (median). The difference between groups was significant (p < 0.0001, Kruskall-Wallis ANOVA test). The Conover post hock test has shown the significant difference for all comparison pairs (p