Taurine Solution Research Articles

Taurine-Functionalized Carbon Nanotubes as Electrode Catalysts for Improvement in the Performance of Vanadium Redox Flow Battery

The vanadium redox flow battery (VRFB) is a highly favorable tool for storing renewable energy, and the catalytic activity of electrode materials is crucial for its development. Taurine-functionalized carbon nanotubes (CNTs) were prepared with the aim of augmenting the redox process of vanadium ions and enhancing the efficiency of the VRFB. Sulfonated CNTs were synthesized through a simple modification process in a taurine solution and used as electrocatalysts for redox reactions involving VO2+/VO2+ and V2+/V3+. The SO3H-CNTs modified at 60 °C for 2 h exhibit the best electrocatalytic activity, showing higher redox peak current values compared to pristine carboxylated CNTs (COOH-CNTs). Sulfonic acid groups added to the surface of CNTs increase active sites for redox reactions and act as carriers for mass transfer and bridges for charge transfer, accelerating the rate of the electrode reactions. A battery consisting of SO3H-CNTs as catalysts demonstrates the outstanding charge–discharge performance at a current density of 300 mA∙cm−2. This configuration displays voltage and energy efficiencies of 81.46% and 78.83%, respectively, representing enhancements of 6.15% and 6.12% compared to that equipped with conventional graphite felts (75.31%, 72.71%). This study illustrates that taurine-functionalized carbon nanotubes serve as an efficient and promising catalyst for both the anode and cathode, leading to the improved performance of the VRFB.

Broad-Purpose Solutions of N-Chlorotaurine: A Convenient Synthetic Approach and Comparative Evaluation of Stability and Antimicrobial Activity

Solutions of N-chlorotaurine (NCT) are effective microbiocidal agents with a broad spectrum of pharmacological activity and outstanding tolerability. The main problem limiting their medical use is their instability, which is generally inherent in solutions of all chlorine-active compounds. In this work, we developed a new synthetic approach to the synthesis of such solutions, which consists in the activation of granular and fibrous polymeric materials with immobilized N-chlorosulfonamide groups, which act here as a chlorinating agent. It was shown that when such polymers are added to taurine solutions, NCT solutions with a chemical composition suitable for immediate medical use can be obtained. The stability of such solutions under various conditions was analyzed in comparison with NCTs obtained by the classical method from sodium hypochlorite. It was confirmed that the process of decomposition of all studied solutions obeys the kinetic laws of the first-order reaction. It was proven that solutions obtained from granular polymers are more stable both in terms of active chlorine concentration and in terms of pH, and their additional buffering is not needed. The stability of solutions decreases when they are stored in the presence of polymers used, with an increase in the excess of taurine and with acidification. The high sensitivity of all obtained solutions to UV radiation was also noted. The antimicrobial properties of NCT solutions obtained from polymers are not inferior to those obtained from sodium hypochlorite at the same concentration of active chlorine. Considering the stability and compactness of the initial chlorine-active polymers, as well as the possibility of their multiple regeneration, the developed method can form the basis of the technology for obtaining multifunctional NCT solutions for medical purposes with the desired physical and chemical properties without using special equipment or specific reagents.

New multifunctional bromine-active polymers: synthesis, properties, and antimicrobial activity

The increase in the frequency and scale of epidemics of infectious diseases gives extreme urgency to the development of new technologies for antiseptic and disinfectant treatment of various media, as well as materials/reagents for their implementation. Antimicrobial polymer materials of various chemical structures, including those containing halogen-active functional groups, are promising in this regard. This work is devoted to the synthesis and investigation of the properties of granular and fibrous polymer materials with immobilized N-bromosulfonamide groups of different structure. It is shown that copolymers of styrene with divinylbenzene and polypropylene can be used as a carrier polymer. A technique has been developed that allows obtaining polymers with a content of up to 23 % of immobilized active bromine. The compliance of the synthesized materials with the declared structure has been proven by IR spectroscopy and a complex of chemical methods. A decrease in the strength of the obtained polymers compared to the original carriers has been observed, especially in the case of fibers. The stability of the synthesized polymers during storage is lower that of the previously described chlorine-active analogs. For the quantitative determination of active bromine in the target materials, a technique based on its rapid diffusion from the polymer into the taurine solution has been developed. Microbiological research has shown that the synthesized polymers have a pronounced antimicrobial activity, which is higher than that of immobilized N-chlorosulfonamides and is manifested even in the presence of a significant organic load. The set of investigated characteristics of synthesized polymers with immobilized N-bromosulfonamide groups suggests the prospect of their use as components of antiseptic dressing materials, antimicrobial filters, devices for obtaining antiseptic solutions, and other medical products

Effects of Taurine as Dietary Supplement on the Biological and Demographic Parameters ofNezara viridula(Heteroptera: Pentatomidae)

The southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), is a widely distributed pest of many economically important crops. Because of its economic impact, multiple examples of rearing methods and diets for N. viridula have been published. However, rearing this pest year-round consistently in all-vegetable diets has been challenging. Preliminary observations have shown that supplementing N. viridula diet with insect components improves the survival and reproduction of this insect. We hypothesized that taurine could be the nutrient present in insect components that was providing the benefits. Treatments consisting of three different watering regimes: 1) Reverse osmosis (RO) water only (W), 2) 2% taurine solution only (T), and 3) a choice between RO water and 2% taurine solution (T&W) were compared for their effects on life cycle and demographic parameters of N. viridula. Both taurine-containing treatments (T and T&W) resulted in a significant increase in nymphal and premating adult survival and egg viability as compared with treatment 'W'. Taurine supplementation did not have significant effect on fecundity and development time significantly increased in the 'T' treatment compared with W and W&T treatments. However, there were significant improvements in demographic parameters showing an increase in fitness levels after taurine supplementation. These results suggest that taurine is an important nutrient for N. viridula, which has been deficient in traditional diets consisting exclusively of vegetable components. Adoption of this new information will help to improve the survival of N. viridula in culture to facilitate this study to develop new methods for its control.

Caloric restriction increases levels of taurine in the intestine and stimulates taurine uptake by conjugation to glutathione

Our previous study indicated increased levels of taurine-conjugated bile acids (BA) in the intestine content of mice submitted to caloric restriction (CR). In the current project, we found increased levels of free taurine and taurine conjugates, including glutathione (GSH)-taurine, in CR compared to ad libitum fed animals in the mucosa along the intestine but not in the liver. The levels of free GSH were decreased in the intestine of CR compared to ad libitum fed mice. However, the levels of oxidized GSH were not affected and were complemented by the lack of changes in the antioxidative parameters. Glutathione-S transferases (GST) enzymatic activity was increased as was the expression of GST genes along the gastrointestinal tract of CR mice. In the CR intestine, addition of GSH to taurine solution enhanced taurine uptake. Accordingly, the expression of taurine transporter (TauT) was increased in the ileum of CR animals and the levels of free and BA-conjugated taurine were lower in the feces of CR compared to ad libitum fed mice. Fittingly, BA- and GSH-conjugated taurine levels were increased in the plasma of CR mice, however, free taurine remained unaffected. We conclude that CR-triggered production and release of taurine-conjugated BA in the intestine results in increased levels of free taurine what stimulates GST to conjugate and enhance uptake of taurine from the intestine.

Вплив одноразового перорального введення щурам асоціату таурин-декстрин на концентрацію амінокислот у плазмі крові

The aim of the study was to test the ability of dextrin particles of different sizes, modified with N-stearylglutamic acid, to increase the transport of taurine into the blood plasma of rats. To achieve this goal, Wistar rats weighing 240–260 g were divided into control and four experimental groups. The control group was administered once perorally with water. The first experimental group was administered perorally with an aqueous solution of taurine at a dose of 100 mg/kg, the second and third ― a solution of taurine-dextrin associate with particle sizes of 60–90 nm and 500–800 nm, in which the dose of taurine was 100 mg/kg. The fourth experimental group (IV) was administered only dextrin. In 30 min, the rats were decapitated, and blood was collected. Blood cells and proteins were precipitated, and samples were derivatized with 1-fluoro-2,4-dinitrobenzene. Free amino acids of plasma were separated on a Dionex Ultimate 3000 liquid chromatograph equipped with a spectrophotometric detector, chromatographic column Luna C18 (2) 250×4.6 mm, elution type was gradient. It was registered that in the first and third experimental groups the content of taurine in the blood plasma of rats was 33.8% higher than in the control. Oral administration of taurine-dextrin associate with 60–90 nm particles increases the taurine content by 62.6% compared to the control and by 21.6% more than in the first and third experimental groups. This indicates efficient transport of taurine by dextrin only with particles of 60–90 nm. Administration of both taurine and taurine-dextrin associate reduced concentrations of glutamine, methionine, lysine, alanine, phenylalanine, and histidine. Moreover, the reason for the decrease in the content of the last two amino acids was not only taurine, but also the transporter itself. With the administration of the transporter the concentration of asparagine was lower than in control, and the content of arginine, on the contrary, higher. In the first experimental group, the concentration of aspartic acid and serine decreased, and in the second ― valine, leucine and tryptophan, in the third ― glutamic acid. The glycine content increased in the second experimental group. Ornithine content in all experimental groups except the third was higher, compared with the control. Thus, modified dextrin with a particle size of 60–90 nm increases the transport of taurine into the blood.

S218. TAURINE DOES NOT PREVENT SOCIAL DEFICITS INDUCED BY MK-801 IN ADULT ZEBRAFISH

BackgroundCognitive and negative symptoms are the core reason for the functional deficits experienced by patients with schizophrenia. Drugs that can modulate these symptoms are especially needed since no progress has been achieved in the last few decades with currently available antipsychotics. Taurine is an amino acid not used for protein synthesis but widely distributed in mammalian tissues. In the central nervous system, it has been shown to act as an inhibitory neuromodulator and possess neuroprotective, antioxidant and immunomodulatory properties. Decreased plasma and brain levels of taurine have been reported in patients as well as in animal models of schizophrenia. Furthermore, taurine improved symptoms and was well tolerated in a clinical trial of patients with first-episode psychosis. We investigated whether taurine counteracts social deficits in a zebrafish model of social interaction following acute exposure to MK-801 (dizocilpine), an NDMA antagonist commonly used in schizophrenia animal models.MethodsNinety-six 3-month-old wild-type zebrafish (Danio rerio, 50:50 male:female ratio) were used. For the social interaction test, animals were individually placed in a beaker with 200 mL of tank water (control) or taurine solution (42, 150 and 400 mg/L) for 20 minutes, and then exposed to water or MK-801 (5 µM) for another 20 minutes (n = 12 animals per group). Immediately after the treatments, zebrafish were transferred to the social interaction apparatus, a tank virtually divided in 3 vertical zones and sided by an empty tank and a tank containing 10 zebrafish. Behavior was recorded for 7 minutes and the last 5 were analyzed by automated tracking with the software ANY-Maze. The time spent in the stimulus zone was measured as a proxy for social interaction; total distance traveled was also computed. Data were analyzed by two-way ANOVA.ResultsMK-801 increased the total distance traveled (F1,88 = 4.935, p = 0.0289) and reduced the time spent in the tank zone next to the conspecifics (F1,88 = 23.14, p < 0.0001). No main effects of taurine or interaction effects were observed on locomotor or social interaction parameters.DiscussionAlthough taurine has been shown to increase social interaction in rats and modulate shoaling behavior in ethanol-exposed zebrafish, it had not been tested against social deficits induced by NMDA antagonists. We observed that taurine did not counteract the hyperlocomotion and social deficit induced by acute exposure to MK-801 in zebrafish. As schizophrenia etiology has been linked to cortical and hippocampal disruption in GABAergic signaling, taurine may be effective as a preventive treatment in early neurodevelopmental stages. Further testing using animal models that more closely resemble the course of schizophrenia are thus needed to investigate the potential of this molecule.

Therapy of Dry Eye Syndrome after Inflammatory Diseases of Cornea

Purpose: evaluation of the efficacy of the drug Tealose® in the therapy of cornea inflammatory diseases consequences such as dry eye syndrome.Patients and methods: 34 patients (34 eyes) with dry eye syndrome after inflammatory diseases of the cornea, aged 28–56 years old were included in the study. Two clinical groups were formed: observation group — 20 subjects (20 eye) and comparison group — 14 subjects (14 eyes). The dynamics of such indicators were estimated under therapy: visual acuity with maximal correction, corneal epithelium entity according fluoresceine dye test, tear production according Schirmer and Norn tests, the grade of dry eye syndrome severity according index of OSDI — Questionnarie. The patients in observation group in addition to the basic therapy, which included instillation antiseptics и 4 % taurine solution, were treated with 3 % solution of tregalose (Tealose®, “Laboratuar Thea”, France) by such mode: using of 4 times daily instillations during 1 month, 1 month break, than continuation of the same regimen instillations during 1 month was performed. The patients in comparison group in addition to the same basic therapy were treated with Visomitin® (“Mitotech”, Russia) by the mode, which was used for tregalose.Results. The improvement of cornea’s epithelization (p &lt; 0,05), increasing of visual acuity with maximal correction (p &lt; 0,05), improvement of tear production (p &lt; 0,05), as well as the OSDI-index (p &lt; 0,05) were revealed in the patients of the observation group. In the patients of the comparison group positive dynamics of these indicators was insignificant and unreliable.Conclusions. Using of 3 % tregalose solution in patients with consequences of inflammatory diseases of the cornea — keratitis leads to effective treatment of “dry eye” syndrome, reduces the severity of epithelization disorders and tendency to scarring in the corneal tissue.

β-Amyloid Peptide Antagonizes the Effect of Protons on Taurine-Induced Chloride Current in Rat Hippocampal Pyramidal Neurons.

Taurine is an important endogenous agonist of glycine receptors (GlyR). Using the patchclamp technique, we measured chloride current induced by a short (600 msec) application of taurine (ITau) on isolated rat pyramidal neurons. pH of taurine solution in the applicator pipette was neutral (7.4) or acidic (7.0-5.0). Application of protons to a neuron causes a dosedependent decrease in the peak amplitude and acceleration of ITau desensitization. Addition of 100 nM β-amyloid peptide (Aβ) to the perfusate caused acceleration of ITau desensitization. The effects of Aβ and H+ on the rate of ITau desensitization were not additive. In addition, Aβ attenuated the effect of H+ on the peak amplitude of ITau. We also studied the effect of protons on the chloride current caused by activation of GABA receptors. In contrast to H+ effects on GlyR, Aβ did not modulate the effects of H+ on GABA receptors.

Taurine Ameliorates High Glucose Induced Apoptosis in HT-22 Cells.

Diabetes causes memory loss. Hippocampus is responsible for memory and increased apoptosis was found in diabetes patients. Taurine improved memory in diabetes condition. However, mechanism is unclear. In current study, hippocampal cell line HT-22 cells were subjected to analysis as five groups i.e. Control, High glucose (HG) at concentration of 150mM, HG+10mM (T1), 20mM (T2) and 40mM (T3) taurine solution. TUNEL assay showed that HG increased the number of apoptotic cell significantly while taurine reduced apoptosis. Taurine increased phosphorylation of Akt in HT-22 cell treated with HG, and increased phosphorylation of Bad (p-Bad) was seen suggesting involvement of Akt/Bad signaling pathway. Expression of Bcl-2 was reduced in HG group but taurine improved this. Bax expression showed opposite trend. This indicated that taurine may reduce apoptosis by controlling balance of Bcl-2 and Bax. When the activation of Akt was blocked by using of perifosine, the effect of taurine disappears either partially or altogether. Thus, it was clear that taurine reduces apoptosis via Akt/Bad pathway in HT-22 cells exposed to HG which further improves downstream balance of Bcl-2 and Bax. This mechanism may be involved in apoptosis of hippocampus cells in diabetic condition.

Protective effect of taurine on cellular structures in rat hippocampus following ethanol intoxication.

Background. Distinct brain structures, in particular, the hippocampus, have a selective sensitivity to acute and chronic alcohol intoxication. Study of the pathogenesis of alcohol-related brain damage with a view to the development of methods of prevention and treatment is an urgent task.Objective.Our main interest was in elucidating the effects of the biologically active substance, such as taurine on cellular structures in the hippocampus following ethanol intoxication.Methods.We applied a histochemical method to estimate the Ca2 + -dependent acid phosphatase activity. The present study was carried out in female albino rats. All experimental animals received an ethanol (15%) diet as their sole source of fluid at various time points.To study the effect of taurine on cellular structures of the rat brain following short-term and chronic alcohol consumption, rats were given daily injections of taurine solution for 7 days. Results. The morphological picture of the hippocampus is characterized by swelling of granular cells in the dentate gyrus that undergo chromatolysis, as well as a decrease in numerical density and a weak expression of processes of pyramidal neurons in the early stages of alcohol consumption. Degenerative changes occur in pyramidal cells in the hippocampus in the middle periods of alcohol consumption. The density of neurons is decreased; pyramidal cells lose their characteristic shape. In the conditions of long-term alcohol consumption, not only changes in the size and number of pyramidal neurons but also in the volume of the hippocampus and its regions are observed. The morphological picture of hippocampal neurons is a morphological proof of the disorders of their metabolism. In rats treated with taurine, there are positive changes in the structural properties of neurons and an increase in phosphatase activity (increased metabolism) in the hippocampus, which determines cell survival and functional recovery of irritated neurons. Conclusion. The results indicate that taurine has a neuroprotective effect on cellular structures in rat hippocampus.

The hydration of selected biologically relevant molecules – the temperature effect on apparent molar volume and compression

The densities and sound velocities at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K were measured for aqueous solutions of glycine, trimethylamine-N-oxide, taurine and N-methylacetamide. From these data, the apparent molar volumes, VΦ, the apparent molar isentropic compressions, KS,Φ, and the Passynski hydration numbers of solutes were determined. The concentration dependencies of the calculated quantities, their limiting values and temperature characteristics are discussed in terms of solute-solvent and solute-solute interactions. The obtained data clearly show strong hydration of the molecules of glycine, trimethylamine-N-oxide and taurine. Opposite effect, i.e. weak interactions with water molecules, is found for N-methylacetamide.

Influence of long-term per oral taurine treatment on activity of liver enzymes in mature rats

Taurine is sulfur-containing derivative of methionin and cysteine that plays a key role in glucose and lipid metabolism. Taurine regulates antioxidant defense system, membrane potential of mitochondria, and glycolysis. Thus, it might have a serious impact on cell metabolism in mammals. The aim of this work was to study the influence of long-term per oral taurine treatment (5, 10 and 20 mg/kg) on the antioxidant defense system, cholesterol content, activity of transaminases and lactate dehydrogenase in rat liver. To achieve that goal, mature Wistar rats (weight 140–160 g, age – 4 months) were divided in four groups – control, rats which once a day during 28 days were injected drinking water in esophagus, and three experimental groups, that were injected taurine solution in concentrations: І – 5 mg/kg, ІІ – 10 mg/kg and ІІІ – 20 mg/kg of body mass. After 28 days, rats were decapitated under light chloroform narcosis and liver mass was determined. In liver, content of cholesterol, TBA-active products and activity of antioxidant defense enzymes, transaminases, and lactate dehydrogenase were measured. Our results show that after a long-term per oral taurine treatment liver mass decreased by 27.5 % comparing to control group. Lactate dehydrogenase activity increased two times, while the activity of alanine aminotranferase and aspartate aminotransferase in mitochondrial fraction increased by 40–90 % in liver of animals of all experimental groups. Total activity of these enzymes in rat liver increased by 20–37 % in all experimental groups. Cholesterol content increased dy 32.4 % in rats of experimental group II. This may indicate intensification of liver metabolism. The content of TBA-active products in submitochondrial and mitochondrial fractions increased more than two times in rats of experimental groups II and III. The activity of superoxide dismutase in the submitochondrial fraction increased by 49.8 and 36.5 % in liver of that rats. The activation of superoxi­de dismutase and a rise in content of TBA-active products may suggest a rise of free oxygen radicals production and inability of antioxidant defense system. These results may indicate a negative influence of taurine in doses higher than 5 mg/kg, since the balance between antioxidant protection and lipid peroxidation processes was violated.

LOW TAURINE CONCENTRATIONS POSSITIVELY AFFECT RABBIT SPERMATOZOA PROPERTIES IN LATER TIME INTERVALS

The aim of this study was to determinate the effect of various taurine concentrations on rabbit spermatozoa in in vitro conditions with the potential use in routine artificial insemination. Taurine, amino acid distinguished by its strong antioxidant properties, has been widely tested on spermatozoa of all kinds of farm animals except for the rabbits. This study investigated differences in rabbit spermatozoa motility and viability between the control sample and samples enriched with taurine solutions: TAU3 (3.125 mM), TAU6 (6.250 mM) and TAU12 (12.5 mM). Ejaculates of nine adult rabbits were subjected to this study and observed at time intervals 0, 90, 180 and 270 minutes while cultivated at 39°C. For detection of viability the MTT test was used and motility parameters were carried out using CASA analysis. Experimental samples were compared against the control. Assessment of the mitochondrial toxicity revealed that the addition of taurine ensured the higher viability in supplemented samples however with no statistical significance. Monitored motility parameters (motility, progressive motility and velocity curved line of spermatozoa) showed that taurine treated spermatozoa have lower activity at the beginning of the study but along with increasing time the positive effect of taurine was induced. Significant (P

The effect of urea and taurine osmolytes on hydrophobic association and solvation of methane and neopentane molecules

The effects of urea and taurine osmolytes on the hydrophobic interactions of methane and neopentane have been studied using molecular dynamics simulations. From the study of potential of mean force, it is observed that both urea and taurine enhance the association of methane and neopentane. The hydrophobic association of methane molecules is stabilized by entropy and destabilized by enthalpy in the mixtures of osmolytes at contact minima while the hydrophobic association of neopentane is stabilized by enthalpy and entropy. In these mixtures, hydrophobic solvation of methane molecules is enthalpy favorable and entropy unfavorable at SSM. The hydrophobic solvation of neopentane is stabilized by entropy and enthalpy. The study of radial distribution functions (RDFs), running coordination numbers, excess coordination numbers of water, urea and taurine molecules around hydrophobic molecules shows that methane shows salting-out (less soluble) and neopentane shows salting-in (more soluble) behavior in aqueous-urea. Methane and neopentane show salting-in behavior in aqueous-taurine solution because of preferential solvation by taurine. Salting-out behavior of methane has been observed in water-urea-taurine mixture. Neopentane shows salting-in behavior in aqueous solution of urea and taurine because of preferential binding with urea. These observations are supported by solvation free energies and spatial density maps.

Taurine and magnesium supplementation enhances the function of endothelial progenitor cells through antioxidation in healthy men and spontaneously hypertensive rats.

Endothelial damage is repaired by endothelial progenitor cells (EPCs), which are pivotal in preventing cardiovascular diseases and prolonging lifespan. The WHO Cardiovascular Diseases and Alimentary Comparison Study demonstrated that dietary taurine and magnesium (Mg) intake suppresses cardiovascular diseases. We herein evaluate the effects of taurine and Mg supplementation on EPC function and oxidative stress in healthy men and spontaneously hypertensive rats (SHRs). Healthy men received taurine (3 g per day) or Mg (340 mg per day) for 2 weeks. SHRs and Wistar-Kyoto (WKY) rats were housed with high-salt drinking water (1% NaCl). The SHRs received 3% taurine solution and/or a high-Mg (600 mg per 100 g) diet for 4 weeks. Their peripheral blood mononuclear cells were separated to quantify EPC colony formation. Oxidative stress markers in their peripheral blood were evaluated using a free radical analytical system and a thiobarbituric acid reactive substance (TBARS) assay. Taurine and Mg supplementation significantly increased EPC colony numbers and significantly decreased free radical levels and TBARS scores in healthy men. Taurine and Mg supplementation significantly increased EPC colony numbers and significantly decreased TBARS scores and free radical levels in SHRs. Nicotinamide adenine dinucleotide phosphate oxidase component mRNA expression was significantly higher in the renal cortex of salt-loaded SHRs than in WKY rats, in which it was suppressed by taurine and Mg supplementation. Taurine and Mg supplementation increased EPC colony formation in healthy men and improved impaired EPC function in SHRs through antioxidation, indicating that the dietary intake of taurine and Mg may prolong lifespan by preventing the progression of cardiovascular diseases.

The effect of urea and taurine as hydrophilic penetration enhancers on stratum corneum lipid models

To optimize transdermal application of drugs, the barrier function of the skin, especially the stratum corneum (SC), needs to be reduced reversibly. For this purpose, penetration enhancers like urea or taurine are applied. Until now, it is unclear if this penetration enhancement is caused by an interaction with the SC lipid matrix or related to effects within the corneocytes. Therefore, the effects of both hydrophilic enhancers on SC models with different dimensionality, ranging from monolayers to multilayers, have been investigated in this study. Many sophisticated methods were applied to ascertain the mode of action of both substances on a molecular scale. The experiments reveal that there is no specific interaction when 10% urea or 5% taurine solutions are added to the SC model systems. No additional water uptake in the head group region and no decrease of the lipid chain packing density have been observed. Consequently, we suppose that the penetration enhancing effect of both substances might be based on the introduction of large amounts of water into the corneocytes, caused by the enormous water binding capacity of urea and a resulting osmotic pressure in case of taurine.

Influence of sodium addition on taurine adduct formation generated in acetic acid/acetate salt buffer applied in LC–MS/MS analysis

To investigate the influence of sodium ion addition on analyte adduct formation generated in acetic acid/acetate salt buffer appropriate infusion experiments of a 1 and 10 μg/mL taurine solution prepared both in methanol with a 1 mmol L−1/10 mmol L−1 CH3COONH4/CH3COOH buffer and with a 1 mmol L−1/10 mmol L−1 CH3COONa/CH3COOH buffer were performed. The results achieved revealed that sodium ion concentration has a relevant influence on taurine adduct formation in the negative electrospray ionisation mode since depending on conditions applied different analyte adducts are favored. Sodium ions which originate from the glassware/chemicals make an effective detection of taurine dimer adducts possible, but taurine adducts with sodium acetate are not formed effectively. On the other side sodium ion addition enables an effective taurine adduct formation with sodium acetate, but taurine dimer based adducts can be observed only at higher analyte concentrations.

Direct Label-Free Measurement of the Distribution of Small Molecular Weight Compound Inside Thick Biological Tissue using Coherent Raman Microspectroscopy

Distributions of small molecular weight (less than 300 Da) compounds inside biological tissue have been obscure because of the lack of appropriate methods to measure them. Although fluorescence techniques are widely used to characterise the localisation of large biomolecules, they cannot be easily applied to the cases with small molecule compounds. We used CARS spectroscopy to detect and identify a label-free small molecule compound. To facilitate detection in aqueous environment, we utilised time-resolved and phase-sensitive techniques to reduce non-resonant background generated from water. We applied this technique to detect small molecular weight compound, taurine, inside mouse cornea tissue immersed in taurine solution as an initial model experiment. We detected a Raman peak of taurine near wavenumber 1033 /cm inside cornea and successfully characterised its depth profile in the tissue. Our CARS spectra measurement can be a promising method to measure and visualise the distribution of small bio-related compounds in biological background without using any labeling, paving the way for new cell biological analysis in various disciplines.Sci. Rep. 5, 13868; http://dx.doi.org/10.1038/srep13868 (2015).

MITOCHONDRIA RESPIRATION AND OXIDATIVE PHOSPHORILATION OF RAT TISSUES AT TAURINE PER ORAL INJECTION

Taurine--sulphur-containing amino acid is a necessary component of mitochondrial matrix, where it maintains pH and is included in mitochondrial transport RNA. But still it is unclear how taurine influences on ATP synthesis and mitochondrial respiration chain components activity. Thus, the aim of the work was to study the effect of long-term per oral taurine injection on mitochondrial respiration intensity in rat tissues: liver, brain, testes and thigh muscle. For this purpose male Wistar rats, that weighted 190-220 g, were divided in three groups, daily during 28 days they were injected drinking water (control group) or taurine solution 40 and 100 mg per kg of body weight (I and II research groups, correspondingly). Respiration intensity was measured polarogrifically with use of Clark electrode at endogenic substrates oxidation (V₁), with exogenic α-ketoglutarate (5 mmol/l) or succinate (1 mmol/l;V₄S) addition, at ADP addition to concentration 200 µmol/l (V₃), and after ADP depletion (V₄ATP). Phosphorylation time, oxidative phosphorilation efficacy (ADP/O), respiratory controls by Lardy (V₃/V₄S) and Chance (V₃/V₄ATP) were calculated. It was found that long term taurine injection increased V₁ in animal brain and liver of both research groups, but it decreased in testes and muscles of I research group. In liver of I research group animals, when both α-ketoglutarate and succinate were oxidated, V₄S, V₃ and V₄ATP were 4-7 times larger than in control. At the same time, Lardy respiratory control increased at succinate oxidation, this may indirectly point on increased coupling between respiration and oxidative phosphorylation. In liver of II research group animals V₄S, V₃ and V₄/ATP when α-ketoglutarate was oxidated were significantly higher than in control. In muscles of I research group V₄S, V₃ and V₄ATP when α-ketoglutarate and succinate was added were lower than in control. In thigh muscle of II research group animals at α-ketoglutarate oxidation V₃ was higher than in control. When succinate was added V₄S and V₄ATP increased in testes mitochondria of both research groups and in brain of I research group. But in II research group animals mitochondria V₄S brain was lower than in control. At the same time, coupling between respiration and oxidative phosphorytation in brain was on control level, in testes of I research group it was lower. In testes of II research group animals at α-ketoglutarate addition increased respiratory controls. Thus, the effect of long term per oral taurine injection on mitochondria respiration intensity is dose-dependent and tissue-specific and, obviously, has different significance and is implemented by different mechanisms.