Witold Reczyński

The role of the GPR39 receptor in zinc deficient-animal model of depression

During the last decade it has been shown that zinc may activate neural transmissions via the GPR39 Zn(2+)-sensing receptor, which can be involved in the regulation of neuronal plasticity. According to the neurotrophic hypothesis of depression, decreased brain derived neurotrophic factor (BDNF) levels in depressed patients play a key role in the pathogenesis of this disorder. BDNF, similarly as zinc, is known to be involved in the process of neuron survival and the regulation of neuronal plasticity. The aim of the present study was to determine whether the administration of a 6-week diet deficient in zinc would cause depressive-like behaviour and if such behavioural alterations would correlate with changes in the expression of the BDNF protein and GPR39 receptor. In the first part of the present study the animal behaviour after a 6-week zinc-deficient diet, in the forced swim test (FST) was investigated. In the second part expression of the GPR39 and BDNF protein level in the frontal cortex was measured using the Western Blot method. Administration of a zinc-deficient diet for 6 weeks increased immobility time in the FST by 24%, so exerted depression-like behaviour. A biochemical study showed a significant reduction in GPR39 (by 53%) and BDNF (by 49%) protein expression in the frontal cortex in mice receiving the zinc deficient diet for 6 weeks. Our study provides evidence that the GPR39 Zn(2+)-sensing receptor may be responsible for lowering the BDNF protein level and in consequence may be involved in the pathogenesis of depression.

Zinc deficiency alters responsiveness to antidepressant drugs in mice

BACKGROUND There is some evidence coming from preclinical and clinical studies suggesting a relationship between dietary zinc intake and depressive symptoms. The aim of the study was to determine whether zinc deficiency alters the response to antidepressants with a different mechanism of action. We examine also whether these changes are related to activity of the hypothalamic-pituitary-adrenal HPA axis. METHODS Male CD-1 mice were assigned to groups according to diet and antidepressant administration. To evaluate animal behavior, the immobility time in the forced swim test (FST) and locomotor activity were measured. To determine serum zinc levels the flame atomic absorption spectroscopy (FAAS) was used. The serum corticosterone was determined by radioimmunoassay (RIA). RESULTS Antidepressants administered to zinc-deprived mice induced an altered response in the FST when compared to animals fed with an adequate diet. There were no changes in locomotor activity. Animals subjected to a zinc-deficient diet showed a significant reduction in serum zinc levels, which was normalized by antidepressant treatment. An increase in serum corticosterone concentrations in mice fed with a zinc-deficient diet and treated with antidepressants was observed, so it can be concluded that reduced levels of zinc contribute hyperactivation of the HPA axis. CONCLUSION The results of this study suggest that a diet with a reduced zinc level alters antidepressant action, which is associated with a reduction in the serum zinc level and rise in the corticosterone level. The results of this study may indicate the involvement of zinc deficiency in the pathogenesis of depression.

Parylene coatings on stainless steel 316L surface for medical applications — Mechanical and protective properties

The mechanical and protective properties of parylene N and C coatings (2-20 μm) on stainless steel 316L implant materials were investigated. The coatings were characterized by scanning electron and confocal microscopes, microindentation and scratch tests, whereas their protective properties were evaluated in terms of quenching metal ion release from stainless steel to simulated body fluid (Hanks solution). The obtained results revealed that for parylene C coatings, the critical load for initial cracks is 3-5 times higher and the total metal ions release is reduced 3 times more efficiently compared to parylene N. It was thus concluded that parylene C exhibits superior mechanical and protective properties for application as a micrometer coating material for stainless steel implants.

Investigation of the GPR39 zinc receptor following inhibition of monoaminergic neurotransmission and potentialization of glutamatergic neurotransmission.

Zinc can regulate neural function in the brain via the GPR39 receptor. In the present study we investigated whether inhibition of serotonin, noradrenaline and dopamine synthesis and potentialization of glutamate, via administration of p-chlorophenylalanine (pCPA), α-methyl-p-tyrosine (αMT) and N-methyl-D-aspartatic acid (NMDA), respectively, would cause changes in GPR39 levels. Western blot analysis showed GPR39 up-regulation following 3-day administration of αMT and NMDA in the frontal cortex, and GPR39 down-regulation following 10-day administration of pCPA, αMT, and NMDA in the hippocampus of CD-1 mice. There were no changes in serum zinc levels. Additionally, we investigated tryptophan, tyrosine and glutamate concentrations in the hippocampus and frontal cortex of GPR39 knockout (GPR39 KO) mice. Liquid chromatography-mass spectrometry (LC-MS) showed a significant decrease in tryptophan and tyrosine, but not in glutamate concentrations in the hippocampus of GPR39 KO mice. There were no changes in the frontal cortex between GPR39 KO and wild type. These results indicate a possible role of the GPR39 receptor in monoaminergic and glutamatergic neurotransmission, which plays an important role in the pathophysiology of depression.

Chemistry of sediments from the Dobczyce Reservoir, Poland, and the environmental implications.

Abstract Sediments samples of the Dobczyce Reservoir (South Poland) were taken in three successive years (2004–06) at 17 points, analyzed for 12 elements by atomic absorption spectrometry. Substantial variations in elemental composition due to hydrological and environmental reasons were found. The use of statistical and chemometric tools enabled objective and effective analysis of the data obtained, both in case of long term observations as well as in terms of interpretation of incidental changes in metal concentrations. The proposed methodology can be useful in: a) dividing monitored territories (lakes, rivers, catchments) into similar and dissimilar areas; b) distinguishing between typical and non-typical contaminants distribution; c) reducing the number of essential analytes and sampling points that should be controlled in the future, without loss of important environmental information.

Dynamics of arsenic-containing compounds sorption on sediments

AbstractBackgroundRiver and lake sediments constitute complex and difficult analytical samples. On the other hand, sediments play a fundamental role in the distribution of toxic compounds in aquatic systems and in the evaluation of the current state and the course of changes taking place in the environment.Among elements present in the environment in trace concentrations, but having well-elaborated toxic properties, one of most dangerous is arsenic. The element occurs in the environment in several chemical forms, predominant are inorganic forms of As(V) and As(III), and methylated forms such as monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA).ObjectivesReported herein are experiments, which were undertaken with the aim of examining the dynamics of arsenic sorption in sediments and its dependence on speciation of the element and the pH in the environment. Simultaneously, influence of organic matter content and chemical composition of the sediments on As sorption, were investigated.MethodsSediment samples (upper 10 cm layer) were collected from three sites located in the vicinity of Cracow:•Rudawa river — 37 km long river, flowing mainly through the suburban area;•Vistula river — heavily contaminated, main Polish river;•Dobczyce reservoir — artificial reservoir on Raba river, total capacity of 125,000,000 m3, supplying about 60% of drinking water to the city of Cracow. Using XRD and IR methods, mineral composition of sediments was analysed. Concentrations of iron, manganese, aluminium and arsenic as well as organic matter content in solid samples were analysed.Sorption experiment100 g of dry sediment sample was placed in a 400 ml volume glass beaker. 300 ml of arsenic containing solution was poured into the beaker. Every 30 min (total experiment time span equalled 7 to 7.5 hours), 0.5 ml of the suspension’ (the beaker content was constantly mixed) was collected and centrifuged, and the concentration of arsenic was determined in the supernatant.In the series of experiments, solution contained about 0.05 µg/ml of arsenic in organic (DMAA) and inorganic forms, at different pH values — 3, 5, 7 and 9.Results and DiscussionExamined sediments of Vistula river and Dobczyce Lake were characterised by relatively high concentrations of arsenic, iron, manganese and aluminium.Rudawa river. At pH 3, the concentration of inorganic As in solution decreased from an initial value of 0.049 µg/ml to 0.012 µg/ml in 7.5 hours time. The same decreasing tendency was found at pH 5 (initial value 0.046 µg/ml, after 7.5 hours - 0.015 µg/ml). Less distinct sorption effects were noted at pH 7 and 9. Vistula river. At all pH values, a very significant decrease of inorganic As concentration up to 80% of the initial value, as well as a short time of achieving an equilibrium state (1 – 2.5 hours), was found. Dobczyce lake. Inorganic As was distinctly accumulated in sediments at pH 3 (decrease of As concentration in solution from 0.052 to 0.007 µg/ml after 7.5 hours of the experiment) and at pH 5. At pH 7, about 40% of As was accumulated in sediments (solution As concentration decrease from 0.050 to 0.030). Only 20% of As adsorbed on sediments at pH 9.Very weak accumulation of organic form of As (DMAA) was found in all examined sediments at pH 3 and 5. At higher pH values no sorption was registered.ConclusionsThe following facts were established:•inorganic form of arsenic was effectively accumulated in all analysed sediments;•inorganic As sorption in sediments strongly depended on pH — for sediments of Rudawa river and Dobczyce lake, the highest sorption was found at pH 3, and a decrease of accumulated As was noted with an increase of pH (at pH 9, the lowest amount of As was immobilised in sediments); in the case of Vistula river sediments, a reverse tendency was found;•organic form of arsenic (DMAA) was accumulated only at pH 3 in all sediments and less significantly at pH 5 (Vistula river sediments); no sorption of that form of As was found in the other sediment samples;•state of equilibrium (no change in inorganic As concentration in liquid medium) was achieved in 1 hour for Vistula river sediments, after about 2 hours for Rudawa river and after about 4 hours for Dobczyce lake sediments.RecommendationsThe presented method of analysis of As sorption in sediments and results visualization (based on a newly defined coefficient) provides a useful tool for the characterization of sorptive properties of sediments and may be used for other compounds as well. Crucial, functional information — how much of a given element may be accumulated in sediments at a certain pH — is obtained without digestion of the sediment sample, in an experiment taking less than one day.

The serum magnesium concentration as a potential state marker in patients with unipolar affective disorder.

AIM The growing body of evidence suggests that magnesium levels can serve as a marker of major depressive disorder (MDD), but findings from clinical trials remain inconclusive. The aim of the presented study was to determine the magnesium concentration in serum of patients with MDD (in the active stage of the disease or in remission) and to analyze the role of magnesium levels as apotential marker of the disease. METHODS Sixty-nine patients with current depressive episode, 45 patients in remission and 50 healthy volunteers were enrolled into the case-control study. The magnesium concentration was measured by flame atomic absorption spectrometry (FAAS). RESULTS The mean serum magnesium concentration of patients in the depressed phase was significantly higher, compared to the control group. Moreover, magnesium levels of patients in the remission were not significantly different from the concentrations recorded in the healthy volunteers. There was also a positive correlation between the magnesium levels and the severity of depression measured by the Hamilton Rating Scale for Depression (HDRS) and the Montgomery-Asberg Depression Rating Scale (MADRS). CONCLUSIONS The obtained results may suggest a role of magnesium as a state marker reflecting the pathophysiological changes underlying MDD and accompanying severe depressive episodes.

The serum concentration of magnesium as a potential state marker in patients with diagnosis of bipolar disorder.

AIM Few scientific reports indicate changes in the concentration of magnesium in the blood of patients with bipolar disorder (BD). So far very little studies concerning these issues have been conducted. Therefore, the aim of this study was to evaluate the serum magnesium level in patients with bipolar disorder (in different phases of the disease) in comparison to healthy volunteers. METHODS The study included 129 patients (58 subjects in depressive episode, 23 in manic episode and 48 patients in remission) with the diagnosis of bipolar disorder type I or II. The control group consisted of 50 healthy people. Magnesium concentration was measured using flame atomic absorption spectrometry (FAAS). RESULTS Patients with a current depressive or manic/hypomanic episode had statistically significantly elevated serum magnesium levels compared to healthy volunteers. Moreover, a positive correlation between the duration of the manic/hypomanic episode and the relapse frequency in the last year was observed. The concentration of magnesium in patients in remission was unchanged in relation to the control group. CONCLUSIONS Presented findings suggest a role of serum magnesium level as a potential state marker, reflecting the pathophysiological changes associated with acute episodes of bipolar disorder.

Lake biota response to human impact and local climate during the last 200 years: A multi-proxy study of a subalpine lake (Tatra Mountains, W Carpathians).

Element content, loss-on-ignition, chironomid analysis and (210)Pb dating were applied on a sediment core from a subalpine Tatra lake (Popradské pleso) to reveal the response of aquatic biota to eutrophication induced by human activities in the lake catchment. The lead dating indicates that the 0-8 cm section of the core represents the past ca 200 years, ending at ~1814 AD. Comparing the key changes of the proxies with human activities that are historically well documented, four phases of the recent lake development were distinguished: (1) a pre-tourism phase, (2) a phase of increasing touristic activity and early cottage development, (3) a phase of eutrophication, and (4) a phase of post-eutrophication. Neither touristic activity, nor early cottage development around the lake (1st and 2nd phases) had considerable influence on the chironomid assemblage structure or organic content of the lake. The most significant change both in chironomid assemblage structure and loss-on-ignition occurred during the 3rd phase, when a big tourist hotel was built close by the lake and started contaminating it via direct wastewater input. However, the structure of the chironomid assemblage has not changed significantly over time and the dominating taxa remained the same during the whole period. Parallel with the nutrient signal of the paleo assemblage, a secondary signal has been identified as the ratio of rheophilic taxa on total abundance that did not correlate with the sediments organic content, and is most likely driven by local climatic oscillations. Changes of most of metal elements concentrations reflected rather bigger scale changes of industrial activities than local scale human disturbances. Our results indicate that hydromorphological properties can moderate the impact of organic pollution on the lake biota.

Kinetics of extracted bioactive components from mushrooms in artificial digestive juices

ABSTRACT This article presents a study on fruiting bodies of Boletus badius, Boletus edulis, Cantharellus cibarius, Lactarius deliciosus, Leccinum scabrum, Suillus bovinus, Suillus luteus, Pleurotus ostreatus, Tricholoma equestre, Armillaria mellea, Agaricus bisporus, and Auricularia polytricha. The amounts of their health-promoting bioelements and physiologically significant indole and phenolic compounds were determined. The significance of edible mushrooms in the human diet and in disease prevention were also established. The high-performance liquid chromatography was used to assess the contents of indole compounds and phenolic acids. The atomic absorption spectroscopy was applied to determine bioelements. In all samples, the content of 5-hydroxy-L-tryptophan was studied. The highest extraction amount of serotonin was found for P. ostreatus species. Phenolic compounds were determined in the conditions described in the present study for the first time. Additionally, protocatechuic, p-hydroxybenzoic, syringic, and gallic acids were determined.