Anode Modification with Fe2O3 Affects the Anode Microbiome and Improves Energy Generation in Microbial Fuel Cells Powered by Wastewater

This study investigated how anode electrode modification with iron affects the microbiome and electricity generation of microbial fuel cells (MFCs) fed with municipal wastewater. Doses of 0.0 (control), 0.05, 0.1, 0.2, and 0.4 g Fe2O3 per the total anode electrode area were tested. Fe2O3 doses from 0.05 to 0.2 g improved electricity generation; with a dose of 0.10 g Fe2O3, the cell power was highest (1.39 mW/m2), and the internal resistance was lowest (184.9 Ω). Although acetate was the main source of organics in the municipal wastewater, propionic and valeric acids predominated in the outflows from all MFCs. In addition, Fe-modification stimulated the growth of the extracellular polymer producers Zoogloea sp. and Acidovorax sp., which favored biofilm formation. Electrogenic Geobacter sp. had the highest percent abundance in the anode of the control MFC, which generated the least electricity. However, with 0.05 and 0.10 g Fe2O3 doses, Pseudomonas sp., Oscillochloris sp., and Rhizobium sp. predominated in the anode microbiomes, and with 0.2 and 0.4 g doses, the electrogens Dechloromonas sp. and Desulfobacter sp. predominated. This is the first study to holistically examine how different amounts of Fe on the anode affect electricity generation, the microbiome, and metabolic products in the outflow of MFCs fed with synthetic municipal wastewater.

Electrodegradation of Acid Mixture Dye through the Employment of Cu/Fe Macro-Corrosion Galvanic Cell in Na2SO4 Synthetic Wastewater

Traditional wastewater purification processes are based on a combination of physical, chemical, and biological methods; however, typical electrochemical techniques for removing pollutants require large amounts of electrical energy. In this study, we report on a process of wastewater purification, through continuous anodic dissolution of iron anode for aerated Cu/Fe galvanic cell in synthetic Na₂SO₄ wastewater solution. Electrochemical experiments were conducted by means of a laboratory size electrolyzer, where electrocoagulation along with electrooxidation phenomena were examined for wastewater containing Acid Mixture dye. The above was visualized through the employment of electrochemical (cyclic voltammetry and ac impedance spectroscopy techniques) along with instrumental spectroscopy analyses.

Low-grade chronic inflammation and immune alterations in childhood and adolescent cancer survivors: A contribution to accelerated aging?

Background

The long‐term consequences of chemotherapy and radiotherapy result in a high prevalence and early onset of age‐related chronic diseases in survivors. We aimed to examine whether childhood and adolescent cancer survivors (CS) demonstrate biomarkers of accelerated aging.

Methods

We evaluated 50 young adult CS at 11 [8–15] years after cancer diagnosis, and 30 healthy, age and sex‐matched controls, who were unexposed to cancer therapy. Using a machine‐learning approach, we assessed factors discriminating CS from controls and compared selected biomarkers and lymphocyte subpopulations with data from the Framingham Heart Study (FHS) cohort and the Genotype Tissue Expression (GTEx) project.

Results

Survivors compared with controls had higher levels of C‐reactive protein and fibrinogen. The surface expression of CD38 on T cells was increased, and there was an increase in the percentage of memory T cells in survivors, compared with the unexposed group. The relationships between above cell subpopulations and age were consistent in CS, FHS, and GTEx cohorts, but not in controls.

Conclusions

Young pediatric cancer survivors differ from age‐related controls in terms of activation of the adaptive immune system and chronic, low‐grade inflammation. These changes resemble aging phenotype observed in older population. Further research in biomarkers of aging in young, adult childhood cancer survivors is warranted, as it may facilitate screening and prevention of comorbidities in this population.

Electrochemical Degradation of Industrial Dyes in Wastewater through the Dissolution of Aluminum Sacrificial Anode of Cu/Al Macro-Corrosion Galvanic Cell

This paper reports on the process of industrial-type wastewater purification carried-out through continuous anodic dissolution of aluminum alloy sacrificial anode for artificially aerated Cu-Al alloy galvanic (macro-corrosion) cells and synthetically prepared wastewater solutions. Electrochemical experiments were performed by means of a laboratory size electrolyzer unit, where the electrocoagulation process along with surface-induced electrooxidation phenomena were examined for wastewater containing Acid Mixture and Disperse Red 167 dyes. Final reduction of the dyes concentrations came to 32 and 99% for Acid Mixture and Disperse Red 167, correspondingly. The above was visualized through the employment of electrochemical (cyclic voltammetry and a.c. impedance spectroscopy techniques) and instrumental spectroscopy analyses.

Situation analysis on evidence-informed health policy-making in Poland

Background

Over the last few years, increased international attention has been paid to bridging the gap between health research and policy-making. The situation analysis on evidence-informed policy-making (EIP) in Poland aims to increase understanding of interactions among a country’s research and policy-making communities, to determine where and how to best establish a knowledge translation platform (KTP), i.e. an organization or network that through its structure and functioning brings the worlds of research and policy together.

Methods

The methods were guided by the EVIPNet Europe Situation Analysis Manual and included a literature review, key-informant interviews and survey data analysis.

Results

In Poland, the existence of incentives or requirements stipulating the use of research evidence in health policy varies, depending on the type of policy. The use of evidence is a standard practice in drug policy, and in decisions related to the inclusion of services in the health benefit package. In other areas, some good practice examples of using evidence in policy can be identified. Yet these are rather individual, isolated and bottom-up initiatives, which neither occur systematically, nor routinely. Key challenges in view of strengthening a systemic approach to EIP relate to: overlapping mandates of key health system and research institutions, generally low research capacity and lack of knowledge translation skills.

Conclusions

Establishing and operationalizing a KTP can be an effective means of supporting sustainable EIP. Building such infrastructure, however, is a longer-term and complex process that needs to be based on the current characteristics of the country’s EIP landscape. The proposed model of a future KTP in Poland is a network with a joint secretariat within the Ministry of Health. Such form can take advantage of existing organizations’ competencies via information exchange and cooperation.

Key messages

Although systemic mechanisms for evidence-informed health policy are missing in Poland, its importance is recognized among major health system stakeholders. The proposed model of a future knowledge translation platform in Poland is a network with a joint secretariat within the Ministry of Health.

Possibilities of fish passage through the block ramp: Model-based estimation of permeability

Block ramps offer an opportunity to combine hydrotechnical structures with fish passages. The primary study objective was to evaluate the effectiveness of a block ramp for upstream fish movement in a mountain stream. Geodetic measurements of the bottom surface and water level were taken for three cross-sections. The description of the geometric and hydrodynamic parameters of the block ramp was supplemented with information on the width and length of crevices between boulders. Measurements of the geometric and hydrodynamic parameters of the block ramp were performed at 76 measurement sites, at three different types of discharge. Ichthyological data were collected in the analyzed stream. Measurements covered among others total length, width, and height of caught fish. Salmonid, cottid, balitorid, and cyprinid fish were studied. The determination of the main effects of the geometric and hydrodynamic parameters of the block ramp on the possibilities of use by target fish species employed generalized linear models (GLMs). The study shows that the block ramp cannot provide longitudinal connectivity and migration of fish occurring in the mountain stream. According to estimates, the block ramp did not meet the permeability expectations. The reason for low usefulness of the ramp for fish is particularly excessively strong water current. The stream concentration constituted an unsurmountable velocity barrier for fish moving upstream for each of the analyzed discharges. The developed model suggests that some crevices in the side zones of the ramp could be parts of the migration corridor, but only for small and medium-sized fish. At medium and high water stages, movement of fish in crevices was difficult due to fast water current, and at low and very low discharges, some crevices lost their permeability, and could become ecological traps for fish. The necessity of estimation of ramp permeability during pre-construction phase was emphasized.

Endothelial dysfunction is independent of inflammation and altered CCR7 T cell expression in patients with ankylosing spondylitis

OBJECTIVES

The accumulation of CCR7 (chemokine receptor 7) positive cells in the vessel wall may be involved in endothelial dysfunction and subsequent accelerated atherogenesis. CCR7 plays a crucial role in T cell and monocyte migration/homing and in priming of naive T lymphocytes in non-lymphoid tissues in chronic inflammatory diseases. Our objective was to investigate the endothelial function and inflammation-driven expression of CCR7 on T lymphocytes in patients with ankylosing spondylitis (AS).

METHODS

We performed flow cytometry to assess the distribution of peripheral blood T cell subpopulations in the context of serum inflammatory markers (TNF-α, IL-6, sICAM-1) and asymmetric dimethylarginine (ADMA) in 38 patients with AS with active disease, and in 20 healthy controls.

RESULTS

Patients with AS demonstrated higher ADMA (0.74±0.2 μmol/l vs. 0.64±0.15 μmol/l; p=0.03), as well as elevated inflammatory markers (TNFα, IL-6, sICAM-1) and increased proportions of circulating CCR7-positive lymphocytes largely attributable to elevated CD8+ naive T cells (47.1±17 vs. 34.3±13.1%; p=0.005). However, ADMA did not correlate with either CCR7-positive lymphocytes or inflammatory markers.

CONCLUSIONS

We found an increased percentage of peripheral CCR7 T cells accompanied by endothelial dysfunction in patients with AS. The lack of direct associations between ADMA and inflammation may suggest the presence of other pathogenic mechanisms contributing to accelerated atherogenesis and increased cardiovascular risk in AS.

The Effect of Treatment of Denture-related Stomatitis on Peripheral T Cells and Monocytes

PURPOSE

Systemic immune activation has been recently linked to chronic inflammatory disorders of the oral cavity, particularly to periodontitis. The purpose of this study was to determine whether treatment of a fungus-induced oral inflammation, namely denture-related stomatitis (DRS), can affect the activation of the systemic immune response.

MATERIALS AND METHODS

Peripheral blood from patients with denture-related stomatitis caused by Candida albicans infection (n = 15) was collected at three time points: before treatment with nystatin, at the end of therapy and 2 months after finishing therapy. Activation of T cells and monocytes was assessed by flow cytometry.

RESULTS

The percentages of peripheral lymphocytes, T cells and their subpopulations, as well as monocytes were similar before, immediately following and two months after nystatin treatment. Cells expressing early activation marker CD69 and RANTES C-C chemokine receptor type 5 significantly increased immediately after treatment and returned to baseline levels after two months. Th17 cells, which have been implicated in the pathogenesis of DRS, remained unchanged. Central memory CD4+ subset and intermediate subset of monocytes were lower after therapy and this effect was sustained for two months.

CONCLUSION

Treatment of denture-related stomatitis does not seem to affect the general state of the cellular components of the immune system. The results suggest a potential proinflammatory effect of the antifungal agent, nystatin. Although transient and not intense, this effect might be of particular clinical importance, because of relationships between inflammation and certain diseases. Further studies are required to clarify this aspect.

Vascular transcriptome profiling identifies Sphingosine kinase 1 as a modulator of angiotensin II-induced vascular dysfunction

Vascular dysfunction is an important phenomenon in hypertension. We hypothesized that angiotensin II (AngII) affects transcriptome in the vasculature in a region-specific manner, which may help to identify genes related to vascular dysfunction in AngII-induced hypertension. Mesenteric artery and aortic transcriptome was profiled using Illumina WG-6v2.0 chip in control and AngII infused (490 ng/kg/min) hypertensive mice. Gene set enrichment and leading edge analyses identified Sphingosine kinase 1 (Sphk1) in the highest number of pathways affected by AngII. Sphk1 mRNA, protein and activity were up-regulated in the hypertensive vasculature. Chronic sphingosine-1-phosphate (S1P) infusion resulted in a development of significantly increased vasoconstriction and endothelial dysfunction. AngII-induced hypertension was blunted in Sphk1^-/- mice (systolic BP 167 ± 4.2 vs. 180 ± 3.3 mmHg, p < 0.05), which was associated with decreased aortic and mesenteric vasoconstriction in hypertensive Sphk1^-/- mice. Pharmacological inhibition of S1P synthesis reduced vasoconstriction of mesenteric arteries. While Sphk1 is important in mediating vasoconstriction in hypertension, Sphk1^-/- mice were characterized by enhanced endothelial dysfunction, suggesting a local protective role of Sphk1 in the endothelium. S1P serum level in humans was correlated with endothelial function (arterial tonometry). Thus, vascular transcriptome analysis shows that S1P pathway is critical in the regulation of vascular function in AngII-induced hypertension, although Sphk1 may have opposing roles in the regulation of vasoconstriction and endothelium-dependent vasorelaxation.

Systemic T Cells and Monocyte Characteristics in Patients with Denture Stomatitis

PURPOSE

Chronic inflammatory disorders of the oral cavity, such as periodontitis, were recently linked to systemic immune activation. Since fungal oral infections have not yet been studied in this respect, the aim of our study is to determine whether the local inflammation caused by oral fungal infection of the palatal tissue (denture stomatitis-DS) is associated with the systemic inflammatory response. This question is becoming essential as the population ages.

MATERIALS AND METHODS

Peripheral blood of DS patients (n = 20) and control patients (n = 24) was assessed with flow cytometry to determine lymphocyte and monocyte profiles. Intracellular cytometric analysis was carried out to establish cytokine production by T cells. DS was diagnosed based on clinical symptoms of DS such as swelling and redness of oral mucosa, confirmed by microbiological swabs for fungal colonization with Candida species. The control group was recruited from denture users without clinical and microbiological signs of oral infections.

RESULTS

Percentages of peripheral lymphocytes, T cells, monocytes, and their subpopulations were similar in both studied groups. The exception was median percentages of CD25+ T cell subsets, which were significantly lower in DS patients than in control subjects. This reduction was observed in both CD4 T cell subset (16.7% and 28.1%; p = 0.0006) and CD8 T cell subset (4.6% and 7.0%; p = 0.007) CONCLUSIONS: While DS and associated local fungal infection do not overtly affect activation of monocytes or lymphocytes, the number of CD 25+ T cells is significantly lower in the DS patients, possibly indicating limited potential for the infection clearance in denture-using aging patients.

Malignant hypertension: new aspects of an old clinical entity

Malignant hypertension (MHT), also known as accelerated-malignant hypertension or malignant-phase hypertension, is the most severe form of arterial hypertension. It is defined clinically as high blood pressure (BP) levels associated with lesions of the retinal fundus (flame-shaped hemorrhages, exudates, or cotton wool spots, with or without papilledema). Despite the availability of a vast range of antihypertensive agents, MHT continues to be a significant clinical challenge. Although its prevalence is very low, the absolute number of new cases has not changed over the past decades. While the role of the activation of the renin-angiotensin-aldosterone system and endothelial dysfunction in the pathogenesis of MHT has been well described, recent studies have indicated that the immune system may also play an important role in the development of this condition. Patients with MHT are characterized by pronounced target organ damage, including structural and functional cardiac abnormalities. MHT is frequently complicated by renal insufficiency and end-stage renal disease. The survival rates for patients with MHT have improved considerably with increased availability of antihypertensive treatment. However, renal insufficiency and end-stage renal disease still remain a significant cause of morbidity and mortality in this patient group. In conclusion, MHT is not a "vanishing disease" because there is a relatively stable number of new cases per year. Nonetheless, prognosis and survival rates in these patients have improved significantly owing to earlier detection, stricter BP control, lower BP targets, better choice of antihypertensive drugs, and availability of hemodialysis and renal transplantation.

Kinetics of electrooxidation of phenol on polycrystalline platinum

This work reports on kinetics of phenol electrooxidation reaction (PhER), examined at polycrystalline Pt electrode in 0.5 M H2SO4 and 0.1 M NaOH supporting solutions. Important aspects of PhER kinetics were analysed based on potential-dependent, a.c. impedance-derived values of charge-transfer resistance and capacitance parameters. Special attention was also given to the influence of supporting electrolyte ions on the process of phenol oxidation (pH dependence of the PhER), in relation to an important role of anion adsorption on the Pt catalyst surface.

Hydrogen evolution reaction at Ru-modified nickel-coated carbon fibre in 0.1 M NaOH

The electrochemical activity towards hydrogen evolution reaction (HER) was studied on commercially available (Toho-Tenax) and Ru-modified nickel-coated carbon fibre (NiCCF) materials. Quality and extent of Ru electrodeposition on NiCCF tows were examined by means of scanning electron microscopy (SEM). Kinetics of the hydrogen evolution reaction were investigated at room temperature, as well as over the temperature range: 20-50°C in 0.1 M NaOH solution for the cathodic overpotential range: -100 to -300 mV vs. RHE. Corresponding values of charge-transfer resistance, exchange current-density for the HER and other electrochemical parameters for the examined fibre tow composites were recorded.

Blood monocyte subsets and selected cardiovascular risk markers in rheumatoid arthritis of short duration in relation to disease activity

OBJECTIVES

To evaluate blood monocyte subsets and functional monocyte properties in patients with rheumatoid arthritis (RA) of short duration in the context of cardiovascular (CV) risk and disease activity.

METHODS

We studied conventional markers of CV risk, intima media thickness (IMT), and blood monocyte subsets in 27 patients aged 41 ± 10 years with RA of short duration (median 12 months) and 22 healthy controls. The RA subjects were divided into low (DAS28: 2.6-5.1) and high (DAS28 > 5.1) disease activity.

RESULTS

RA patients exhibited increased levels of intermediate (CD14(++)CD16(+)) monocytes with decreased CD45RA expression compared to controls, increased counts of classical (CD14(++)CD16(-)) monocytes, and decreased percentages of nonclassical (CD14(+)CD16(++)) monocytes. Patients with high disease activity had lower HLA DR expression on classical monocytes compared to low disease activity patients. There were no differences in monocyte subsets between subjects with DAS > 5.1 and DAS ≤ 5.1. There were no significant intergroup differences in IMT and the majority of classical CV risk factors.

CONCLUSIONS

Patients with RA of short duration show alteration in peripheral blood monocyte subsets despite the fact that there is no evidence of subclinical atherosclerosis. Disease activity assessed with DAS28 was associated with impaired functional properties but not with a shift in monocyte subpopulations.

Markers of thrombogenesis and fibrinolysis and their relation to inflammation and endothelial activation in patients with idiopathic pulmonary arterial hypertension

Background

Chronic anticoagulation is a standard of care in idiopathic pulmonary arterial hypertension (IPAH). However, hemostatic abnormalities in this disease remain poorly understood. Therefore, we aimed to study markers of thrombogenesis and fibrinolysis in patients with IPAH.

Methods

We studied 27 consecutive patients (67% female) with IPAH aged 50.0 years (IQR: 41.0 - 65.0) and 16 controls without pulmonary hypertension. Prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin (TAT) complexes were measured to assess thrombogenesis; tissue-type plasminogen activator (tPA) antigen and plasmin-anti-plasmin complex to characterize activation of fibrinolysis; plasminogen activator inhibitor 1 (PAI-1) to measure inhibition of fibrinolysis; and endothelin-1 (ET-1) and interleukin-6 (IL-6) to assess endothelial activation and systemic inflammation, respectively. In addition, in treatment-naive IPAH patients these markers were assessed after 3 months of PAH-specific therapies.

Results

TPA (10.1[6.8-15.8] vs 5.2[3.3-7.3] ng/ml, p<0.001), plasmin-anti-plasmin (91.5[60.3-94.2] vs 55.8[51.1-64.9] ng/ml, p<0.001), IL-6 (4.9[2.5-7.9] vs 2.1[1.3-3.8] pg/ml, p=0.001) and ET-1 (3.7 [3.3-4.5] vs 3.4[3.1-3.5], p= 0.03) were higher in patients with IPAH than in controls. In IPAH patients plasmin-anti-plasmin and tPA correlated positively with IL-6 (r=0.39, p=0.04 and r=0.63, p<0.001, respectively) and ET-1 (r=0.55, p=0.003 and r=0.59, p=0.001, respectively). No correlation was found between tPA or plasmin-anti-plasmin and markers of thrombogenesis. Plasmin-anti-plasmin decreased after 3 months of PAH specific therapy while the other markers remained unchanged.

Conclusions

In the present study we showed that markers of fibrynolysis were elevated in patients with IPAH however we did not find a clear evidence for increased thrombogenesis in this group of patients. Fibrinolysis, inflammation, and endothelial activation were closely interrelated in IPAH.

Changes in exercise capacity and cardiac performance in a series of patients with Eisenmenger's syndrome transitioned from selective to dual endothelin receptor antagonist

BACKGROUND

Differences in clinical effects between selective and dual endothelin (ET) receptor antagonists (ERA) in patients with pulmonary arterial hypertension (PAH) are currently unknown. We aimed to assess prospectively how transition from selective (sitaxsentan) to dual (bosentan) ERA affected exercise capacity and cardiocirculatory performance in patients with Eisenmenger's syndrome.

METHODS

A series of seven stable patients with Eisenmenger's syndrome aged 40.0 (30.0-56.0) years old treated with sitaxsentan were assessed before and three months after transition to bosentan. Six minute walk test and magnetic resonance to assess LV and RV mass, volume and ejection fraction, and pulmonary flow, and laboratory tests were performed.

RESULTS

We observed an increase in LV mass [96.5 (66.0-116.0) vs. 123.0 (93.0-146.0)g; p=0.03], LV ejection fraction [55.0 (44.0-63.0) vs. 65.0 (58.0-70.0)%; p=0.02)], and pulmonary flow [64 (53.0-71.0) vs. 69.0 (55.0-84.0)ml/beat; p=0.046]. This was accompanied by an increase of oxygen saturation, elongation of 6MWD [435.0 (378.0-482.3) vs. 474 (405.0-534.7); p=0.02], decrease of NTproBNP level and increase of ET-1 level.

CONCLUSIONS

Three month follow-up of stable patients with Eisenmenger's syndrome transitioned from sitaxsentan to bosentan revealed improvement of exercise capacity despite significant elevation of ET-1 level. Concurrent increase of LV ejection fraction and pulmonary flow might have contributed to these favourable effects.

Sub-lethal photodynamic damage to ARPE-19 cells transiently inhibits their phagocytic activity

Efficient phagocytosis of photoreceptor outer segments (POS) membranes by retinal pigment epithelium (RPE) plays a key role in biological renewal of these highly peroxidizable structures. Here, we tested whether photodynamic treatment, mediated by merocyanine 540 (MC 540), rose Bengal or a zinc-substituted chlorophyllide inhibited phagocytic activity of ARPE-19 cells in vitro. Specific phagocytosis of fluorescein-5-isothiocyanate-labeled POS isolated from cow retinas and nonspecific phagocytosis of fluorescent polystyrene beads were measured by flow cytometry. Photodynamic treatment, mediated by all three photosensitizers with sub-threshold doses, induced significant inhibition of the cell-specific phagocytosis. The nonspecific phagocytosis was inhibited by photodynamic treatment mediated only by MC 540. The inhibition of phagocytosis was a reversible phenomenon and after 24 h, the photodynamically treated cells exhibited phagocytic activity that was comparable with that of untreated cells. This study provides proof of principle that sub-threshold photodynamic treatment of ARPE-19 cells with appropriate photosensitizers is a convenient experimental approach for in vitro study of the effects of oxidative stress on specific phagocytic activity of RPE cells. We postulate that oxidative damage to key components of the cell phagocytic machinery may be responsible for severe impairment of its activity, which can lead to retinal degeneration.

Influence of long-term exposure to dietary cadmium on growth, maturation and reproduction of goldfish (subspecies: Prussian carp Carassius auratus gibelio B.)

The influence of long-term exposure of goldfish to dietary cadmium (Cd) on its accumulation in tissues, growth, ovarian development, luteinizing hormone (LH) secretion and a response to hormonal stimulation of spawning were evaluated. The study was conducted on four groups of females for the period of 3 years, from the age of 10 weeks to second spawning. Four doses of Cd were applied in the feed: 0 (control group), 0.1, 1 and 10 mg Cd g(-1) of feed (wet weight). The highest dose of Cd (10 mg g(-1)) inhibited growth and caused several behavioural effects. In contrast, lower dose of Cd (1 mg g(-1)) stimulated fish growth. The doses of Cd from 0.1 to 1 mg Cd g(-1) did not influence ovarian development. The gonado-somatic index (GSI) and histological analysis of ovaries showed no differences in ovarian development between the control group and the groups receiving these doses of Cd. However, in the group receiving the highest Cd dose, GSI decreased. This was associated with persistent, long-lasting elevation of plasma LH levels. Ovulation did not occur in this group. Injections of salmon GnRH-analogue (sGnRHa) alone or with domperidone (a dopamine receptor antagonist) in sexually mature fish caused an increase of LH levels in all groups, although in the group fed with the highest Cd dose the effect was weaker than in the other groups. After the first spawning season, a negative effect of lower Cd doses (0.1 and 1mg Cd g(-1)) on ovarian recrudescence (rebuilding of ovaries) and on the response to the consecutive hormonal stimulation of spawning was observed (lower number of ovulating females). There was a significantly higher content of Cd in the livers of fish than in their muscles. The results of hormonal stimulation of spawning and histological analysis of ovaries suggest that in goldfish cadmium acts mainly at the level of ovary rather than on the pituitary gland. We suppose that in the natural environment cadmium present in the feed can play an important role in the accumulation of this element in fish tissues and can influence vital physiological processes.

The influence of gabaergic drugs upon LH secretion from the pituitary of the common carp: an in vitro study

In the present study, the perifusions of whole pituitary glands of spermiating male common carp were performed in the presence of several GABAergic drugs. Muscimol (agonist of GABA(A) receptors) and bicuculline (the antagonist of the same type of GABA receptors) did not modify basal LH release. LH basal secretion was not modified when pituitaries were perifused with baclofen--an agonist of GABAB receptors. On the other hand, baclofen at doses of 10(-8) and 10(-4) M significantly decreased GnRH-A-induced LH release to about 86% and 88% of LH levels in control group, respectively. In our previous study we have shown that GABA decreased basal and GnRH-A-stimulated in vivo and in vitro LH release. In conclusion, it can be suggested that in the mature male carp GABA exerts an inhibitory influence on GnRH-stimulated LH release, probably through the inhibition of the GnRH action on gonadotropes. This inhibition seems to be mediated by the B type of GABA receptors.