Membranotropic Effect Research Articles

Kinetic biopharmaceutical studies of a new paracetamol–glucosamine analgetic drug

Background: Intercomponent drug interactions could play important role for drug release, membrane permeability and membranotropic action. Therefore, newly developed drugs need for checking their biopharmaceutical characteristics. A new analgetic drug based on paracetamol (Actimask® Acetaminoprofen) and a hepatoprotector N-acetyl-D-glucosamine has been developed, with increased safety and potentiation of the analgesic effect (Ruban O., 2022). Multibilayer lipid membranes were chosen as promising testing medium due to their proved appropriation and sensitivity for study multi-compound drug-membrane interactions. It is the basis for a kinetic approach allowing elucidation of biopharmaceutical interactions in model membrane medium. Objectives: Revealing changes of paracetamol release and membrane penetration in the new paracetamol-glucosamine analgetic drug as well as estimation the rationale of the approach developed to trace biopharmaceutical interactions in model membrane medium. Materials and Methods: L-a-dimyristoyl phosphatidylcholine (DMPC) multibilayer membrane was used as a model biomimetic testing medium. Differential scanning calorimetry (DSC) was applicated to trace kinetics of drug-membrane interactions. Results: Gelatin as a part of Actimask® increased the characteristic time of paracetamol diffusion about threefold, but it had no pronounced effect on the equilibrium paracetamol penetration into the membrane. Sole glucosamine manifested no membranotropic effect under the experimental conditions, however, in combination with gelatin, it sufficiently reduced equilibrium paracetamol penetration while paracetamol diffusion remained within the experimental error. The full drug formulation increased membrantoropic effect by 34 % in compared with sole paracetamol. Conclusions: Glucosamine and gelatin can affect both kinetic and equilibrium parameters of paracetamol-membrane interactions, while the full set of the drug components is able to increase the effect which correlates well with the previously established enhancement of analgetic effect of the drugs. The approach developed allows accurate tracing of drug release and membrane penetration depending on a set of drug components. Generally, the results obtained prove the rationale of applying the approach to pre-clinical drug examination.

Effect of Modified Levopimaric Acid Diene Adducts on Mitochondrial and Liposome Membranes.

This paper demonstrates the membranotropic effect of modified levopimaric acid diene adducts on liver mitochondria and lecithin liposomes. We found that the derivatives dose-dependently reduced the efficiency of oxidative phosphorylation of mitochondria due to inhibition of the activity of complexes III and IV of the respiratory chain and protonophore action. This was accompanied by a decrease in the membrane potential in the case of organelle energization both by glutamate/malate (complex I substrates) and succinate (complex II substrate). Compounds 1 and 2 reduced the generation of H2O2 by mitochondria, while compound 3 exhibited a pronounced antioxidant effect on glutamate/malate-driven respiration and, on the other hand, caused ROS overproduction when organelles are energized with succinate. All tested compounds exhibited surface-active properties, reducing the fluidity of mitochondrial membranes and contributing to nonspecific permeabilization of the lipid bilayer of mitochondrial membranes and swelling of the organelles. Modified levopimaric acid diene adducts also induced nonspecific permeabilization of unilamellar lecithin liposomes, which confirmed their membranotropic properties. We discuss the mechanisms of action of the tested compounds on the mitochondrial OXPHOS system and the state of the lipid bilayer of membranes, as well as the prospects for the use of new modified levopimaric acid diene adducts in medicine.

Design, Spectral Characteristics, Photostability, and Possibilities for Practical Application of BODIPY FL-Labeled Thioterpenoid.

This paper presents the design and a comparative analysis of the structural and solvation factors on the spectral and biological properties of the BODIPY biomarker with a thioterpene fragment. Covalent binding of the thioterpene moiety to the butanoic acid residue of meso-substituted BODIPY was carried out to find out the membranotropic effect of conjugate to erythrocytes, and to assess the possibilities of its practical application in bioimaging. The molecular structure of the conjugate was confirmed via X-ray, UV/vis-, NMR-, and MS-spectra. It was found that dye demonstrates high photostability and high fluorescence quantum yield (to ~100%) at 514–519 nm. In addition, the marker was shown to effectively penetrate the erythrocytes membrane in the absence of erythrotoxicity. The conjugation of BODIPY with thioterpenoid is an excellent way to increase affinity dyes to biostructures, including blood components.

State of antioxidant system in urogenital trichomoniasis and membranotropic effect of metronidazole

The objective of this work was to study the activity of glutathione peroxidase, glutathione reductase and the level of sulfhydryl groups in erythrocytes of patients with urogenital trichomoniasis and the effect of metronidazole on the degree of osmotic and peroxide resistance of erythrocytes from healthy donors. We examined 15 patients with urogenital trichomoniasis and 20 healthy volunteers. We studied native preparations, and also carried out a culture method using the Johnson-Trussel nutrient medium (CPLM) to identify Trichomona vaginalis. The activity of glutathione reductase, glutathione peroxidase and the level of total sulfhydryl groups were determined in erythrocytes of peripheral blood. The membrane effect of metronidazole was evaluated in in vitro experiment by the degree of osmotic and peroxide resistance of erythrocytes from healthy people. It has been established that a significant decrease in glutathione reductase and glutathione peroxidase activities in erythrocytes is observed, which indicates a violation of the antioxidant system in this pathology. It was shown in vitro experiment, that metronidazole in low concentration (80 μmol /l) has the ability to inhibit erythrocyte hypotonic hemolysis, and high concentration (250 μmol/l) leads to a decrease in osmotic and peroxide resistance of erythrocytes. Thus, inhibition of the activity of the enzymatic link of the antioxidant defense is observed in urogenital trichomoniasis, which is one of the mechanisms for the development of pathology at the cellular level in this disease. It has been shown that the isolated membranotropic action of metronidazole depends on its concentration – the drug at low concentration is able to inhibit hypotonic hemolysis of erythrocytes, and high concentration makes them more sensitive to the osmotic and peroxide hemolysis. The obtained results should be taken into account in the development of complex methods of therapy for urogenital trichomoniasis.

The Synergy of Membranotropic Effect of the Two Pla2 Fractions of Macrovipera lebetina obtusa Venom on the Model Membranes.

It is known that snake venoms are a complex of enzymes and proteins and the interaction of different venom components with the membranes could be significantly enhanced in course of their action in an orchestra. The aim of the proposed investigation is to obtain detailed information about the mechanism and topology of two snake venom PLA2 isoforms from the Macrovipera lebetina obtusa venom in the membrane-binding process. We investigated the impact of the interaction on the properties of the model membrane (namely, GUVs and erythrocytes ghost) for each of these isoforms, as well as their synergetic action if they act simultaneously. The 6-lauroyl-2-dimethylaminonaphthalene and 6-propionyl-2-dimethylaminonaphthalene fluorescence probes were used to allow us to determine the membrane polarity more accurately via a generalized polarization function. Our results show that two types of PLA2 bring viscosity reduction in GUVs membrane and the effect became more potent when these PLA2 acts together. Intriguingly, we have not observed any significant difference in the case of the erythrocytes ghost membrane.

An Anti-microbial Terpenoid Fraction from Gymnema sylvestre Induces Flip-flop of Fluorescent-Phospholipid Analogs in Model Membrane.

Therapeutic potential of Gymnema sylvestre on diverse cell types is predominantly due to a variety of terpenoids and their derivatives. However, their bioavailability becomes limited due to poor solubility and lower lipophilic properties, provoking the search for novel membranotropic terpenoids and their mechanism of action. A terpenoid fraction purified from Gymnema sylvestre exhibited broad spectrum antimicrobial activity against both Gram positive and Gram negative bacteria with IC50 ˂ 0.1mg/ml. Evaluation of its membranotropic effect in vitro on reconstituted model membrane revealed that the fraction induced flip-flop of fluorescent phospholipid analogs across the lipid bilayer. The terpenoid-induced lipid flipping was biphasic with a fast linear phase (rate constant (k1) = 3 to 5S-1) and a second slow exponential phase (rate constant (k2) = (4 to 9) × 10-3S-1). The lipid-flippase activity of the terpenoid fraction showed concentration and incubation-dependent cooperativity, indicating their lipophilic nature and membrane-destabilizing activity that facilitated lipid translocation. For the first time, our study reveals the flippase activity of a terpenoid fraction of Gymnema sylvestre that could be further explored for their membrane-mediated pharmacological properties. Graphical Abstract.

Implementation of the method of acidic erythrograms to reveal the membranotropic effect of biologically active peptides

The method of acidic erythrograms was used to study the membranotropic effect of biologically active peptides (BAP). The air exposure of erythrocyte suspension in isotonic sodium chloride solution caused a decrease in their resistance to acid hemolysis: the time of hemolysis decreased, the integral indicator of erythrocyte resistance decreased too. The air exposure of erythrocyte suspension with the BAP solutions (10-8M) changed the hemolytic resistance of erythrocytes. It was found out that a non-opiate analogue of leu-enkephalin (NALE – Phe-D-Ala-Glu-Phe-Leu-Arg), Selank (Thr-Lys-Pro-Arg-ProGly-Pro) and Semax (Met-Glu -His-Phe-Pro-Gly-Pro) increase the resistance of erythrocyte membranes to acid hemolysis, and the Arg-Gly-Arg-Pro-Gly-Pro peptide decreases the resistance of erythrocyte membranes to acid hemolysis. Membranotropic action can determine the nonspecific effects of BAP and the range of their clinical use. Acidic erythrograms can be used as a screening method for the selection of BAP with membranotropic effects.

In quest of effect directed analysis in the smart laboratory: Automated system for flow-through evaluation of membranotropic effects of emerging contaminants

The rate-determining step of the human exposome workflow is the acquisition of physiologically relevant data (e.g., effect directed analysis), which can be performed retrospectively or with ad hoc experiments. In this contribution, an automated system is proposed for evaluating potential interaction mechanisms of xenobiotics across cell membranes, the so-called membranotropic effects, using liposomes as a mimicry of biological membranes, and fluorescent membrane probes. The smart fluidic method features real-time acquisition of fluorescence readouts, data processing and feedback in a fully unsupervised mode. As a proof of concept applicability, the behavior of newly synthesized cholesterol-laden biomimetic liposomes, and the in-vitro potential toxicant action of bisphenol A and diclofenac as model of emerging contaminants on cell membrane surrogates were investigated in a flow-through format. Unattended operation resulted in excellent intermediate precision (<1.5%) and unveiled that diclofenac affected the liposomal bilayer order very slightly, regardless of the cholesterol concentration, because it accumulates at a superficial level, while the membranotropic effect of bisphenol A was more pronounced at low concentration levels of cholesterol because at increased levels, the membrane reduces its permeability.

DETERMINATION OF THE ACTUAL PROPERTIES OF GLUCOSAMIN HYDROCHLORIDE IN EXPERIMENTS WITH SUFFICIENTLY SPEED PHYSICAL LOADING

Relevance. Glucosamine hydrochloride, as a medicament, is introduced in various fields of medicine. Its frigidoid and cardioprotective properties have been determined, but its protective properties have not been determined yet. There is a need to substantiate the expediency of using glucosamine hydrochloride as a metabolic and metabolitotropic agent, as improving performance and accelerating recovery processes under extreme conditions and under physical stress.&#x0D; Objective. Investigate possible acto-protective properties of glucosamine hydrochloride in an experiment on rats at high-speed physical activity.&#x0D; Materials and methods. Experiments were performed on 35 white rats in males of the Wistar line, weighing 180-200 g. Rapid loading was created by running rats at Tredbani with a tape speed of 42 m / min and on the test "swimming with additional load to full exhaustion". Glucosamine hydrochloride was administered intragastrically at a dose of 50 mg / kg using a probe for 10 days. Under the thiopental-sodium anesthesia, decapitations were performed, myocardial, liver, and skeletal muscle were removed, in which the content of the components of prooxidant-antioxidant homeostasis (level of LO-diene conjugates (DK), secondary malonic dialdehydes (MDA), superoxide dismutase enzymes activity (SOD), catalase).&#x0D; Results. Introduction of glucosamine hydrochloride lengthened swimming time in rats by 59% and running time by 52%, which indicates the adaptive and act-protective effect of the agent. During a high-speed run, without the use of an actoprotector, the level of lipid peroxidation (DC, MDA) increases and the activity of antioxidant protection enzymes (SOD, catalase) decreases. However, when using glucosamine hydrochloride, the level of lipid peroxidation (DC, MDA) decreases and the level of antioxidant protection (SOD, catalase) increases, which proves its act-protective properties. So, glucosamine hydrochloride prevents a change in the indices of prooxidant-antioxidant homeostasis, which is explained by the presence of a membranotropic and antioxidant effect in it.&#x0D; Conclusions. Glucosamine hydrochloride has its protective properties. The implementation of the actoprotective action may be mediated due to antioxidant effects.

Efficiency of treatment of patients with non-alcoholic steatohepatitis combined with diabetes mellitus type 2 using the s-adenosylmethionin

Non-alcoholic fatty liver disease is an important cause of chronic liver damage in many countries and is growing rapidly in both adults and children due to obesity and diabetes type 2. Aim — investigate the effectiveness of complex treatment of patients for the course of NASH using S-adenosylmethionin on the background of basic therapy. The study included 25 patients with non-alcoholic steatohepatitis against type 2 diabetes, age on average (58.69±1.25) years. The control group comprised 15 healthy individuals. In order to identify the diagnosis, data from clinical and laboratory, biochemical and instrumental studies were fully integrated into account. Statistical processing of the results was carried out using Statistica 6.1. In the group of patients with NASH before treatment, the stage I of hepatosis was observed in 15% of cases, the second — in 50%, the third in 35%. Lipid blood spectrum revealed high levels of low and very low density lipoprotein and low levels of high density lipoprotein. High levels of triglycerides among men and high thyroid test among women were determined. The results of the complex (with the inclusion of S-adenosylmethionine) treatment for patients with NASH showed a significant improvement in the subjective state of patients: reduced complaints of discomfort in the right hypochondrium, general weakness, nausea and dizziness. In the ultrasound study in the group of NASH, the redistribution of the number of patients in the side with the reduction of heavier stages of hepatosis was observed: the number of patients with stage I hepatosis was determined in 52.9% of cases (an increase of 3.5 times), stage II — in 24.9% (reduction in 2 times), the third stage — in 22,2% (reduction by 1,5 times). Among all patients, the cytolysis, mesenchymal-inflammatory syndrome, cytology, hemograms improved, and lipid and metabolic parameters were stabilized, confirming the positive membranotropic effect of S-adenosylmethionin on the membrane structures of hepatocytes and indicating anti-inflammatory, hepatoprotective and regenerative effects of the drug in the treatment of patients with steatohepatitis combined diabetes mellitus type 2.

Biochemical markers of safety of nano-particles of metals on the model of isolated subcultural fractions of eukaryotes

Unique sizes and a high level of bioavailability allow nanoparticles of metals (NPMe) to come into direct contact with biological systems, with infectious agents, toxins, as well as with different chemical compounds and separate cell structures (proteins, lipids, nucleic acids). Other biological effects, including less toxicity than in microscopic substances, require attention to be paid to the study of the potential risk of using nanoparticles of each type in a particular way, therefore scientific support is absolutely necessary in this direction. It is believed that the cytotoxicity of nanomaterials is due to genomic and mutagenic effects, but the mechanical forces of interaction of NPMе with cells, obviously, will change not only cytological but also their metabolic reactions. Therefore, the purpose of this research was to determine the biochemical markers of safety (potential toxicity) of NPMe (Au, Ag, Cu, Fe, Co, GFCo, Zn, MnO2) on the model of isolated membrane and cytosolic fractions of eukaryotic test cells of CHO-K1 and U937 lines. Under conditions of preincubation of experimental samples of NPMe at a final concentration of 1 μg/cm3 by the metal with preparations of subcellular fractions of CHO-K1 and U937 (in the final amount of protein 150–200 μg/cm3) for 3 minutes at 37 ± 1 ºС, there was determined the magnitude of membrane ATP-ase and cytosolic LDH-ase activity compared to intact cells ("control"). According to the results of the research, colloidal dispersions of NPAg average size ~30 nm, NPFe ~100 nm, NPCu ~70 nm, and NPMnO2 ~50 nm are safe and biocompatible by their membranotropic effect on subcellular fractions of eukaryotic test cells, as evidenced by an increase in the level of membrane ATPase and cytosolic LDHase of test-cells CHO-K1, and the experimental samples NPCo, NPGFCo and NPZn average size of ~100 nm are membrane-toxic, that is, dangerous. By the nature of the changes in the enzymatic activity of the test cells U937, the discrete dimensions of the membranotropic action of NPAu have been demonstrated: nanoparticles of size ~10 nm caused the inhibition of the membrane Na+,K+-ATPase, and the size of ~30 nm and ~45 nm – its induction; nanoparticles of size ~10, ~20 and ~30 nm induced cytosolic LDHase and the size of ~45 nm – its inhibition relative to the control level of enzymes, so NPAu ~10 and ~45 nm can be considered membrane toxic, and size ~30 nm – safe and biocompatible for eukaryotic cells. Based on the hypothesis about the involvement of metabolism-dependent mechanisms of contact interaction of colloidal dispersions of experimental samples of NPMe with cells through membranotropic properties, the study of their potential danger or biocompatibility in further research can be carried out by determining the intensity of oxidation of the main structural components of biomembranes of cells – lipids and proteins and indicators of their AO-regulation.

The effect of synthetic antioxidants, anphen derivatives, on erythrocyte morphology

The effect of new synthetic antioxidants, anphens, on erythrocyte morphology was studied. Insignificant cell transformations induced by the hydrophilic derivative of anphen-1 into echinocytes, as well as cell transformations into stomatocytes under the action of hydrophobic derivatives of anphens-2, 3, and 4 were revealed. The data we obtained indicate the intercalation of these compounds into the erythrocyte membrane. The distribution of compounds in the intra-membrane space depends on their hydrophobicity. A hydrophilic compound, anphen-1, is predominantly located in the outer monolayer of the membrane, while hydrophobic derivatives occur in the inner monolayer. It is proposed that the biological activities of anphen-3 and anphen-4 can occur in both monolayers as they move through the membrane, while the hydrophilic compound, anphen-1, exerts an insignificant membranotropic effect and can act only in the outer monolayer of the membrane. Variability in the efficiency of the concentration-dependent modifying action of the compounds with different hydrophobic properties has been found.

The characteristics of interactions of pharmaceuticals and their active ingredients with lipid membranes

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 νОН 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 νОН 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 study of the antioxidant and membranotropic activities of equinochrome a using different model systems

Echinochrome A (6-ethyl-2,3,5,7,8-pentahydroxy-1,4-naphthoquinone) isolated from the body of sand dollar Scaphechinus mirabilis is an active substance of cardioprotective medication Histochrome and exerts a wide spectrum of anti-inflammatory activities. In the present paper, we conducted a comparative study of the antioxidant (radical-scavengering) properties of echinochrome A in 2,2′-azobis(2-methylpropionamidine) dihydrochloride−luminol and hemoglobin−hydrogen peroxide−luminol systems and assessed its impact on permeability of planar bilayer lipid membranes. Trolox was used as a reference antioxidant and ascorbic acid and dihydroquercetin are taken as standards. Echinochrome A shows moderate antioxidant activity, possessing higher antioxidant capacity than Trolox and ascorbic acid, but exhibiting lower antioxidant potential compared with dihydroquercetin in tests for antioxidant activity in both investigated systems. The test substances can be arranged in the following order according to the effectiveness of the antioxidant effect: dihydroquercetin > echinochrome A > Trolox > ascorbic acid. Echinochrome A does not lead to significant changes in the permeability of planar bilayer membranes in a dose range of 1.5 to 30 μМ. Our data indicate that echinochrome A has a rather high level of radical-scavengering activity without a primary membranotropic effect. It is thought that the high levels of the cardioprotective and anti-inflammatory activities of echinochrome A may be due not only to the ability of this substance to neutralize reactive oxygen species, but also to its capacity to generate physiological concentrations of hydrogen peroxide molecules in biological systems as signaling messengers of various metabolic processes and biochemical pathways. The suspected mechanisms of the biological activity of echinochrome A are discussed.

A study of the antioxidant and membranotropic activities of luteolin using different model systems

Luteolin, a water-insoluble 3′,4′,5,7-tetrahydroxyflavon, is one of the best-studied representatives of bioflavonoids. Luteolin is an essential food component for humans and other mammals that possesses a wide spectrum of biological activities by affecting the activities of various metabolic enzymes, target receptors, and signal transduction pathways. In this study, we conducted a comparative study of the antioxidant (free-radical scavenging) properties of luteolin in 2,2′-azobis(2-methylpropionamidine) dihydrochloride–luminol and hemoglobin–hydrogen peroxide–luminol systems and assessed its effect on the permeability of planar lipid bilayer membranes. Trolox was used as a reference antioxidant, while ascorbic acid and dihydroquercetin were taken as standards. Luteolin shows moderate antioxidant activity, exhibiting a higher antioxidant capacity than trolox and ascorbic acid, but it was less effective than dihydroquercetin in tests for antioxidant activity in the studied systems. The studied compounds can be ranked according to the effectiveness of their antioxidant action: dihydroquercetin > luteolin > trolox > ascorbic acid. It should be noted that the antioxidant activity of a water-soluble form of luteolin, luteolin disulfate, is comparable with that of luteolin. Luteolin does not cause significant changes in the permeability of planar bilayer membranes in the dose range from 1.5 to 30 μM. Our findings indicate the presence of a high level of free-radical scavenging activity and the absence of a primary membranotropic effect for luteolin. It can be assumed that the multiple pleiotropic nature of luteolin activity towards a variety of biological systems is associated not only with a neutralizing effect in regard to reactive oxygen species, but also with the ability of luteolin to block and modulate different cell-signaling processes and biochemical pathways. The presumed mechanisms of the biological activity of luteolin and luteolin disulfate are discussed.

Properties of aqueous-saline human placental extracts and their fractions after storage of placenta at various subzero temperatures

Objective: In this study we analyzed the influence of low temperature storage of placental tissue on the effect of obtained aqueous-saline placental extracts and their extract fractions on the state of membranes and cytosol of erythrocytes. Methods: Fractions of human placenta extract (HPE) were obtained with gel-chromatography method. Spontaneous hemolysis of erythrocytes was measured spectrophotometrically by free hemoglobin content in supernatant at 543 nm wavelength. Osmotic fragility (resistance) of erythrocytes was assessed by the level of hemolysis in 0.45% NaCl solution. Low-pH resistance of erythrocytes was evaluated by the time of 50% hemolysis in sodium-phosphate-citrate buffer (pH 3.8), calculating the data from kinetic curve of the change of optical density at 700 nm. Electron paramagnetic resonance (EPR) spin probe method was applied for analysis of cytosol dynamic state. Results: We recorded that low temperature storage of placental tissue allows decreasing membranotropic effect, which was inherent to certain aqueous-saline placental extracts and some of their fractions. At the same time, storage of placental tissue at both 20 С and 196 С does not influence the ability of HPE to decrease erythrocyte osmotic fragility. Erythrocytes exposed with HPE derived from placenta stored for 6 months at 20 С displayed decrease of low-pH resistance. This effect was inherent not only to the whole placental extract, but also to its certain fractions, especially those with molecular weight below 5 kDa. Conclusions: Storage of placental tissue at 196 С seems to be advantageous for preservation of studied properties of placental aqueous-saline extract in comparison to storage at 20 С.

Porphyrin-fullerene nanoparticles for treatment of hypoxic cardiopathies

In this study, low-toxic fullerene-based nanocationite particles (adducts of porphyrin with cyclohexyl fullerene C60) designated for targeted delivery of the paramagnetic stable magnesium isotope to heart muscle is reported for the first time; these particles exhibit a sharp clinical effect of 80% recovery from tissue hypoxia in less than 24 h after a single injection (0.03–0.1 LD50). This therapy is based on a novel principle: 25Mg2+ released by nanoparticles due to the magnetic isotopic effect selectively stimulates the additional production of ATP in oxygen-depleted cells. These cationite “smart nanoparticles,” which possess a membranotropic effect, release hyperactivating paramagnetic cations only in response to a metabolic acidic shift. The final positive changes in the energy metabolism of heart muscle cells are capable of helping to prevent and/or treat local hypoxia of heart muscle, and therefore, protect heart muscle from serious damage in a wide variety of clinical cases of hypoxia, including cardiotoxic side effects of doxorubicin and 1-methylnicotineamide. Both the pharmacokinetics and pharmacodynamics of the proposed drug allow safe and efficient administration in single-and multi-injection (acute and chronic) therapeutic schemes.

Nongenomic effect of androgens on Ca2+ concentration in human lymphocytes

Testosterone and its high-molecular-weight form (testosterone covalently immobilized on bovine serum albumin) induced a rise of intracellular calcium concentration. The effectiveness of dihydrotestosterone was much lower compared to that of testosterone. Gestagens drospirenone and, to a lesser extent, 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one prevented the testosterone-induced Ca(2+) entry into cells. Antagonist of intracellular androgen receptors cyproterone acetate had no effect on testosterone-induced variations in calcium concentration. Human lymphocytes can be used as an experimental test system for screening and evaluation of the molecular mechanisms of nongenomic membranotropic effect of androgens and new compounds with antiandrogen activity.

Membranotropic effects of glucocorticoids. Effect of hydrocortisone on D-glucose uptake by isolated hepatocytes

Hydrocortisone immobilized on polyvinylpyrrolidone did not affect D-glucose uptake by hepatocytes, while free hydrocortisone in a concentration of 10 μM or higher decreased the initial rate of this process. Hydrocortisone-induced inhibition was dose-dependent and related to a decrease in the maximum rate of D-glucose uptake. Polyvinylpyrrolidone-immobilized hydrocortisone potentiated the effects of free hormone. Membranotropic effect of hydrocortisone on D-glucose transport into hepatocytes was associated with a decreased number of glucose carrier molecules or their turnover, rather than with lowered affinity of transport systems for glucose.

Effect of low-intensity laser radiation on cells

Low-intensity (0.89 μ) laser irradiation of mast cells in rat mesentery in various combinations of power and exposure modifies their functional activity. Enhanced degranulation was observed at 18–25 mW beam power and 15–30 sec exposure. The modes of radiation that did not promote degranulation, changed the form of the cells, which indicates a membranotropic effect of low-intensity laser radiation.