Concentrations Of Lead Acetate Research Articles

INVESTIGATE THE IMPACT OF ZINC OXIDE NANOPARTICLES UNDER LEAD TOXICITY ON CHILLI (CAPSICUM ANNUUM L)

Capsicum annuum L is a commercially significant and valuable crop throughout the world. Weather variations and other stresses can significantly affect the growth and productivity of plants and limit crop productivity. One of the biggest stresses is lead poisoning since it hinders agricultural output and growth. Plants undergo biochemical, physiological, and morphological alterations in response to lead toxicity. As a result, the use of nanoparticles as an emerging method can significantly increase crop productivity. In this study, Kiar plants were employed to synthesize zinc oxide nanoparticles. Seed priming was performed using various applications of ZnO-NPs solution. In a field experiment, chilli plants were cultivated with various concentrations of lead acetate. Two different concentrations (250mg L-1 and 500mg L-1) were administered into the root zone. The following measurements were made after the ZnO nanoparticle supplementation: total chlorophyll content, carotenoids, peroxidase, catalase, flavonoids, and total phenolics content. Root and shoot length, fresh root weight and shoot weight, and dry root weight and shoot weight were all included in the morphological study. Nonetheless, the most noteworthy outcomes, proving that the concentration of ZnO-NPs affected chilli plants, was obtained upon applying the particles at a 150 ppm concentration. In comparison to untreated plants, the outcomes demonstrated that all plants treated with ZnO nanoparticles performed better when under stress.

Lead acetate-based test strip method for rapid and quantitative detection of residual sulfur dioxide in Chinese herbal medicines.

To prevent the residual sulfur dioxide in Chinese herbal medicines (CHM) caused by sulfur fumigation, which may lead to severe health issues, there is an urgent need for a rapid and quantitative detection technique. Sodium borohydride was used as a reducing agent to convert sulfur dioxide into hydrogen sulfide, which was then detected using lead acetate test strip. An accurate testing apparatus was designed, consisting of reaction bottle cap, reaction bottle, lead acetate test strip, and sulfur dioxide detector. The effect of different reaction variables on detection, including reductant quality, pH of initial media, reaction time, lead acetate concentration, and membrane type was investigated. The optimal conditions were determined by orthogonal experiments. The reaction membrane type and lead acetate concentration on the membrane were optimized to enhance detection accuracy. Standardized gray cards were fabricated and used to calibrate the detector. The detection system demonstrated an exceptional linear correlation (r2 = 0.9992), with a linear detection range of 0-750 mg·kg-1. The colored substances and sulfur-containing substances within the matrix of CHM did not affect the detection results. Therefore, the detection method exhibited superior accuracy and stability. The proposed technique proved to be swift, reliable, and provides a straightforward and convenient approach for the quantitative determination of sulfur dioxide in CHMs. The results of this work may provide insights into the development of test strips for quantitative detection.

Acute lead (Pb2+) exposure increases calcium oxalate crystallization in the inner medullary collecting duct, and is ameliorated by Ca2+/Mg2+-ATPase inhibition, as well as Capa receptor and SPoCk C knockdown in a Drosophila melanogaster model of nephrolithiasis

Calcium oxalate (CaOx) kidney stones accumulate within the renal tubule due to high concentrations of insoluble deposits in the urine. Pb2+-induced Ca2+ mobilization along with Pb2+-induced nephrotoxic effects within the proximal tubule have been well established; however, Pb2+ mediated effects within the collecting duct remains insufficiently studied. Thus in vitro and ex vivo model systems were treated with increasing concentrations of lead (II) acetate (PbAc) ± sodium oxalate (Na2C2O4) for 1 h, both individually and in combination. Pb2+-mediated solution turbidity increased 2 to 5 times greater post-exposure to 75, 100 and 200 μM Pb2+ with the additional co-treatment of 10 mM oxalate in mouse inner medullary collecting duct (mIMCD-3) cells. Additionally, 100 μM and 200 μM Pb2+ alone induced significant levels of intracellular Ca2+ release. To validate Pb2+-mediated effects on the formation of CaOx crystals, alizarin red staining confirmed the presence of CaOx crystallization. Pb2+-induced intracellular Ca2+ was also observed ex vivo in fly Malpighian tubules with significant increases in CaOx crystal formation via Pb2+-induced intracellular Ca2+ release significantly increasing the average crystal number, size, and total area of crystal formation, which was ameliorated by tissue-specific SPoCk C transporter and Capa receptor knockdown. These studies demonstrate Pb2+-induced Ca2+ release likely increases the formation of CaOx crystals, which is modulated by a Gq-linked mechanism with concurrent Ca2+ extracellular mobilization.

Fabrikasi dan Karakterisasi Bioplastik Timbal Sebagai Bahan Alternatif Proteksi Radiasi Sinar-X

X-ray radiation is widely used in the medical field for early detection of a health disorder. Radiation can pose a danger to its users, one of which is genetic mutation. The use of radiation shields can minimize the adverse effects of radiation. Lead (Pb) is widely used as a constituent of radiation shields. Bioplastics are attractive substitutes for petrochemical plastics due to their biodegradability, renewables, and resource abundance. Cassava and corn starch can be used to make bioplastics. In this study, researchers fabricated radiation protection materials made from biodegradable plastic or bioplastic with varying concentrations of lead acetate doping as a radiation shielding element. A mixture of cassava starch and lead acetate as a radiation protection agent can be suggested as an alternative. Based on research conducted with variations in composition between cassava starch and lead acetate 45:55 data on the effectiveness of the resulting radiation absorption of 49.4%. Based on the shape of the surface topography of the SEM image, which results in a relatively balanced mixture of content, the grouping of lead content is relatively even. However, based on the results of the EDX, there is an anomaly in the amount of weight content of cassava starch; this is suspected because the authors used cassava starch without the addition of synthetic ingredients, so the resistance to the temperature needs to be reviewed. Keywords: bioplastics, cassava starch, lead acetate, radiation shield, SEM, EDX

Lead and cadmium co-exposure modified PC12 viability and ER stress: study from a 3×3 factorial design.

Although exposure to individual metal does exhibit its toxicity, combined exposures provide a more effective representation of the toxic effects of different heavy metal exposures on public health as well as ecosystems. Furthermore, there are few studies on composite exposure to low concentrations of heavy metals, which is more consistent with real-life exposure. The purpose of this study was to explore the neurotoxicity induced by combined exposure to low concentrations of Lead (Pb) and cadmium (Cd) and the potential interaction of their mixture in vitro. PC12 cells were incubation with the corresponding concentration of cadmium chloride and/or lead acetate. Viability of PC12 cells was measured by CCK8 assay after 12, 24 and 48h incubation. Next, We measured the ROS, mitochondrial membrane potential (MMP) and apoptosis produced by different treated cells using ROS assay kit, JC-1 MMP assay kit and annexin V-FITC/propidium iodide (PI) apoptosis assay kit, respectively. Expression of proteins related to PI3K/AKT and endoplasmic reticulum (ER) stress in PC12 cells were tested by western blotting. Our study was the first to analyze the interaction between Pb and Cd using a 3 × 3 factorial design approach to observe neurotoxicity. The results showed that the combined exposure of them was more cytotoxic than the single metal. The activation of PI3K/AKT signaling pathway and several parameters related to oxidative stress and ER stress were significantly altered in combined exposure to low concentrations of Pb and Cd compared with the Pb or Cd. Regarding apoptosis and ER stress, a synergistic interaction between Pb and Cd was evident. Moreover, evoked ER stress as a mechanism involved in the apoptosis of PC12 cells by the combined exposure to Pb and Cd. The present study provides a theoretical basis used for the toxicological assessment of metal mixtures induced neurotoxicity of concern in terms of public health, and more effective control measures should be taken for the environmental pollution caused by various mixed heavy metals discharged from industry and agriculture.

Biochemical changes in the gill, liver, and muscle tissue of Anabas testudineus on exposure to varying concentration of Lead acetate

AbstractHeavy metal pollution in aquatic systems is a global concern because of its toxicity, persistent nature, and its bioaccumulation. The present study was carried out to understand the sub‐lethal effects of lead acetate on Anabas testudineus despite its ability to tolerate stress. Fish were exposed to various concentrations of lead acetate (1.291, 1.936, 3.873 mg/L) for a period of 96 h for assessment of acute toxicity. Various biochemical (protein and glycogen) and enzymatic parameters (acid phosphatase, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase) were investigated to have an insight on lead acetate toxicity. Protein content increased in all tissues in comparison to the control group. Glycogen increased in gill and muscle tissue whereas it decreased in liver tissues. Increase in the activity of phosphatase enzyme was observed in all tissues of the experimental group in comparison with the control group. All the studied parameters in different tissues were normalized to score values for calculation of integrated biomarker index (IBR) for better interpretation of data. Biomarker response index (BRI) was also calculated for a simple indication of the health status of control and experimental fish. Higher BRI value indicates less toxic effect on liver cells due to detoxification process, whereas lead acetate was found to be toxic for both gill and muscle tissue due to low BRI value. Lead acetate induced changes in the physiology of the experimental fish A. testudineus and the parameters taken into account can serve as biomarkers of lead acetate toxicity.

Hyperhalophilic Diatom Extract Protects against Lead-Induced Oxidative Stress in Rats and Human HepG2 and HEK293 Cells.

This work investigated the protective effects of microalga Halamphora sp. extract (HExt), a nutraceutical and pharmacological natural product, on human lead-intoxicated liver and kidney cells in vitro and in vivo in Wistar rats. The human hepatocellular carcinoma cell line HepG2 and the human embryonic kidney cell line HEK293 were used for the in vitro study. The analysis of the fatty acid methyl esters in the extract was performed via GC/MS. The cells were pretreated with HExt at 100 µg mL-1, followed by treatment with different concentrations of lead acetate, ranging from 25 to 200 µM for 24 h. The cultures were incubated (5% CO, 37 °C) for 24 h. Four groups, each containing six rats, were used for the in vivo experiment. The rats were exposed to subchronic treatment with a low dose of lead acetate (5 mg kg-1 b.w. per day). Pretreating HepG2 and HEK293 cells with the extract (100 µg mL-1) significantly (p < 0.05) protected against the cytotoxicity induced by lead exposure. For the in vivo experiment, the biochemical parameters in serum-namely, the level of malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)-were measured in the organ homogenate supernatants. HExt was found to be rich in fatty acids, mainly palmitic and palmitoleic acids (29.464% and 42.066%, respectively). In both the in vitro and in vivo experiments, cotreatment with HExt protected the liver and kidney cell structures and significantly preserved the normal antioxidant and biochemical parameters in rats. This study discovered the possible protective effect of HExt, which could be beneficial for Pb-intoxicated cells.

Modulatory effect of Picralima Nitida on oxidative stress: Cobalt, thiol, total protein in Drosophila melanogaster exposed to lead

Drosophila melanogaster, commonly known as fruit fly, vinegar fly, is a small model organism used in the study of various disciplines. D. biochemical, neurological and physiological sim ilarities with human beings and has about 75% functional homologs of genes causing diseases in humans. Picralima nitida is a diseases in humans. Picralima nitida is a therapeutic herb used in ethnomedicine for the management of several disease conditions. Theobjective of this study is to induce oxidative stress in Drosophila melanogaster using lead and determine its effect on the levels of selected oxidative stress parameters. Determining the potential modulatory effect of Picralima nitida on selected oxidative stress parameters in lead-induced oxidative stress in Drosophila melanogaster was also known in this study. The phytochemicals of Picralima nitida, and survival rate in Drosophila melanogaster exposed to different concentrations of lead and/or Picralima nitida in meal were also studied. A total of 250 Drosophila melanogaster flies were seen in each of the 9 groups (A-I). Group A was used as the control group and was fed with normal standard meal with water only. Group B were fed with 0.25mg/dl lead acetate meal, group C were fed with 1mg/dl lead acetate meal, group D were fed with 10mg/kg Picralima nitida meal, group E were fed with 100mg/kg Picralima nitida diet, group F were fed with 0.25mg/dl lead acetate and 10mg/kg Picralima nitida diet, group G were fed with 1 mg/dl lead acetate and 10mg/kg Picralima nitida diet, group H were fed with 0.25mg/dl lead acetate 100mg/kg Picralima nitida meal and group I were fed with 1mg/dl lead acetate and 100mg/kg Picralima nitida diet. After about 5 days, flies were homogenized and the supernatant recovered were then used for the various biochemical and survival assay, Cobalt was determined with inductively coupled plasma - mass spectrometry, total protein was determined with Lowrys method and total thiols was determined with Ellman's method. The results showed that lead at various concentrations had a toxic effect on the level of oxidative stress parameters (cobalt, thiols, total protein) in Drosophila melanogaster. While Picralima nitida a medicinal plant had a modulatory effect on the level of oxidative stress parameters (Cobalt, total thiols, total protein) in lead- induced Drosophila melanogaster, although it can become toxic when taken in high concentration. All varying concentrations of lead acetate or/and Picralima nitida reduced the survival rate in the flies. From this study it could be deduced that at low concentration Picralima nitida has modulatory effect on oxidative stress.

Effect of Cadmium and Lead Stress on Seed Germination and Seedling Growth of Jatropha curcas L.

Heavy metal pollution in the biosphere has become a worldwide problem. Metal industry effluents, mining sites, municipal and agricultural waste are important sources of metal dispersion in environment. Heavy metal imposed phytotoxicity affects seed germination, seedling growth, photosynthesis and other physiological processes. Exposure of seeds to cadmium (Cd) and lead (Pb) has deleterious effects resulting into inhibition of germination, delayed germination time and retardation of seedling growth due to toxicity. The aim of this research is to investigate the toxic effects of Cd and Pb on seed germination and seedling growth of Jatropha curcas L. and evaluate its tolerance for heavy metal stress. The experimental treatments included exposure to five concentrations of cadmium nitrate and lead acetate (ranging from 25 to 125 µM/L), under which the germination and seedling growth parameters were determined periodically. The germination and growth of J. curcas L. was affected by cadmium and lead supplemented at different concentrations and the toxicity effects were found to be concentration dependent. Tolerance indices declined sharply with increasing concentrations of lead and cadmium treatments. Germination was inhibited upto 50% by 100 μmol/L of Cd, 125 μmol/L of Pb. Mean germination time and seedling vigour index also gradually decreased with increase in Cd and Pb concentration. Cadmium proved to be more toxic than lead in all considerations.

Effect of Cadmium and Lead Stress on Seed Germination and Seedling Growth of Jatropha curcas L.

Heavy metal pollution in the biosphere has become a worldwide problem. Metal industry effluents, mining sites, municipal and agricultural waste are important sources of metal dispersion in environment. Heavy metal imposed phytotoxicity affects seed germination, seedling growth, photosynthesis and other physiological processes. Exposure of seeds to cadmium (Cd) and lead (Pb) has deleterious effects resulting into inhibition of germination, delayed germination time and retardation of seedling growth due to toxicity. The aim of this research is to investigate the toxic effects of Cd and Pb on seed germination and seedling growth of Jatropha curcas L. and evaluate its tolerance for heavy metal stress. The experimental treatments included exposure to five concentrations of cadmium nitrate and lead acetate (ranging from 25 to 125 µM/L), under which the germination and seedling growth parameters were determined periodically. The germination and growth of J. curcas L. was affected by cadmium and lead supplemented at different concentrations and the toxicity effects were found to be concentration dependent. Tolerance indices declined sharply with increasing concentrations of lead and cadmium treatments. Germination was inhibited upto 50% by 100 μmol/L of Cd, 125 μmol/L of Pb. Mean germination time and seedling vigour index also gradually decreased with increase in Cd and Pb concentration. Cadmium proved to be more toxic than lead in all considerations.

Study of lead-induced neurotoxicity in cholinergic cells differentiated from bone marrow-derived mesenchymal stem cells.

The developing brain is susceptible to the neurotoxic effects of lead. Exposure to lead has main effects on the cholinergic system and causes reduction of cholinergic neuron function during brain development. Disruption of the cholinergic system by chemicals, which play important roles during brain development, causes of neurodevelopmental toxicity. Differentiation of stem cells to neural cells is recently considered a promising tool for neurodevelopmental toxicity studies. This study evaluated the toxicity of lead acetate exposure during the differentiation of bone marrow-derived mesenchyme stem cells (bone marrow stem cells, BMSCs) to CCholinergic neurons. Following institutional animal care review board approval, BMSCs were obtained from adult rats. The differentiating protocol included two stages that were pre-induction with β-mercaptoethanol (BME) for 24h and differentiation to cholinergic neurons with nerve growth factor (NGF) over 5days. The cells were exposed to different lead acetate concentrations (0.1-100μm) during three stages, including undifferentiated, pre-induction, and neuronal differentiation stages; cell viability was measured by MTT assay. Lead exposure (0.01-100μg/ml) had no cytotoxic effect on BMSCs but could significantly reduce cell viability at 50 and 100μm concentrations during pre-induction and neuronal differentiation stages. MAP2 and choline acetyltransferase (ChAT) protein expression were investigated by immunocytochemistry. Although cells treated with 100μm lead concentration expressed MAP2 protein in the differentiation stages, they had no neuronal cell morphology. The ChAT expression was negative in cells treated with lead. The present study showed that differentiated neuronal BMSCs are sensitive to lead toxicity during differentiation, and it is suggested that these cells be used to study neurodevelopmental toxicity.

Changes on the structure of the gill apparatus of Cyprynus carpio under the influence of lead and copper

One of the urgent problems of aquatic toxicology is the increasing impact of heavy metals on hydrobionts. The aim of the study was to analyze the effect of high concentrations of lead acetate and copper acetate on carp gills during short-term exposure European carp (Cyprinus carpio carpio) was selected for the study weighing 1250 ± 136 g. During the experiment, 3 groups of 10 individuals were formed - a control group contained in water without a toxic agent; 1 experimental group of fish was contained in a solution of lead acetate (Pb(CH3COO)2) with a concentration of 0.6 mg/l (exceeding the maximum permissible concentration of lead for fishery reservoirs by 100 times); 2 the experimental group of fish was contained in a solution of copper acetate (Cu(CH3COO)2) with a concentration of 0.1 mg/l (exceeding the MPC of copper for fishery reservoirs by 100 times). The structure of the carp gill apparatus was studied by making a temporary wet preparation of the gill petals and its subsequent microscopy. The observed deviations in the state of the gills for the concentrations of copper and lead used included swelling and swelling of the gills, thickening of the epithelium, hypersecretion of the mucous cells of the gills.

Influence of lead acetate on seed germination and growth of young alfalfa plants

This study presents the results of testing the effect of different concentrations of lead-acetate on seed germination and young Seedlings of alfalfa. Тhe experiment was organized so that in the first variant, only lead-acetate of different concentrations (10-5, 10-4, 10-3, 10-2 and 2 x 10-2 M) was used, and in the second, next to the lead acetate EDTA concentration of 0.012 % was added. The results of this study in which natural conditions are imitated showed that the percentage of alfalfa seed germination decreases with increasing lead-acetate concentrations. In a medium of high concentration of lead acetate 10-2 and 2 x 10-2, a small number of seeds (39% and 32 (32%) germinated. In the same treatments with EDTA, the toxic effects of lead acetate were reduced, and seed germination was better (59% and 43% seeds germinated). It has been noticed that lead has toxic effects on the growth of alfalfa roots and stems. In the variant in which EDTA was used, the negative influence of lead on and growth of alfalfa seedlings was significantly mitigated.

Influence of lead acetate on seed germination and growth of young alfalfa plants

This study presents the results of testing the effect of different concentrations of lead-acetate on seed germination and young Seedlings of alfalfa. Тhe experiment was organized so that in the first variant, only lead-acetate of different concentrations (10-5, 10-4, 10-3, 10-2 and 2 x 10-2 M) was used, and in the second, next to the lead acetate EDTA concentration of 0.012 % was added. The results of this study in which natural conditions are imitated showed that the percentage of alfalfa seed germination decreases with increasing lead-acetate concentrations. In a medium of high concentration of lead acetate 10-2 and 2 x 10-2, a small number of seeds (39% and 32 (32%) germinated. In the same treatments with EDTA, the toxic effects of lead acetate were reduced, and seed germination was better (59% and 43% seeds germinated). It has been noticed that lead has toxic effects on the growth of alfalfa roots and stems. In the variant in which EDTA was used, the negative influence of lead on and growth of alfalfa seedlings was significantly mitigated.

Assessment of Cytogenotoxicity Induced by Lead Acetate on Root Tip Cells of Onion (Allium cepa L.)

The aim of present study was to assess the cytotoxic and genotoxic potency of lead acetate using an Allium root tip bioassay. Root tips of Allium cepa L. were treated with different concentrations of lead acetate viz., 0.03, 0.06, and 0.09 mg mL-1 of lead acetate for 48 h. Mitotic index (MI), phase index (PI), and total chromosomal abnormalities (TA) were calculated. The effect of lead acetate was found to be dose-dependent. The frequency of MI ranged from 8.4 to 5.7%, PI of prophase from 4.2 to 3.4%, PI of metaphase from 1.14 to 1.11%, PI of anaphase from 1.8 to 0.6%, and PI of telophase from 1.1 to 0.4% The total chromosomal abnormality (TA) ranged from 0.42 to 1.39% The differences between the averages of all the studied properties were significantly affected by the heavy metal lead acetate concentration variant applied. Mitotic observation showed that increasing of concentration variants doses decrease mitotic index and increased chromosomal abnormality percentage. Various types of physiological and clastogenic (laggard, stickiness, abnormal metaphase, chromatin bridge, and delayed anaphase were observed in Allium cepa root tip cells. Moreover, the A. cepa root tip bioassay method gives critical data for evaluating an agent's action mechanisms and impacts on genetic material.

Changes in glucose concentration in the blood serum of carp due to exposure to heavy metals

The article deals with one of the most urgent problems of aquatic toxicology - the impact of heavy metals on the body of fish. The aim of the study was to analyze glucose indicators in carp after exposure to various concentrations of lead acetate, cadmium, zinc and copper. The experiment included 4 series of experiments, each of which was dedicated to a specific metal (lead, cadmium, zinc, copper). During the research, 1 control group (10 fish) was formed, and in each series of experiments, 3 experimental groups (10 fish) were formed. Experimental groups of fish were contained in a solution of heavy metal acetate with concentrations exceeding the MPC of heavy metals for fishery reservoirs by 10, 100 and 1000 times, respectively. The concentration of serum glucose was studied. An increase in glucose concentration due to heavy metal poisoning was found. However, exposure to 10 and 1000 MPC of zinc leads to a decrease in the concentration of glucose in the blood.

The effects of lead exposure on the expression of IGF1R, IGFBP3, Aβ40, and Aβ42 in PC12 cells

BackgroundTo investigate the effects of lead exposure and IGF1R inhibitor AG1024 on the expression of IGF1R and IGFBP3 in PC12 cells. It is clear that the mechanism of the related proteins inducing AD is regulated by them, thus providing theoretical guidance for the prevention and treatment of lead poisoning. MethodsThis study is mainly used PC12 neuron cell to cultivate and establish a corresponding lead exposure model, deal with cells with different concentrations of lead acetate respectively, divide the experiment into control group, 1 μmoL/L PbAc, 10 μmoL/L PbAc group, IGF1R inhibitor (AG1024) group, IGF1R inhibitor group (AG1024) + 1 μmoL/L PbAc group, IGF1R inhibitor group (AG1024) + 10 μmoL/L PbAc group, respective contamination’s three periods of time 24 h, 48 h, and 72 h. Lead exposure dose on cell proliferation was examined by MTT. The protein expression of IGF1R and IGFBP3 in PC12 cells were tested by western blotting and immunohistochemistry, The expression of Aβ40 and Aβ42 in cell supernatant was determined by ELISA. ResultsCompared with the control group, the proliferation of the cells in the high-dose lead-exposed group was significantly inhibited (P < 0.05), and the expression of IGF1R and IGFBP3 was significantly decreased (P < 0.05); the contents of Aβ40 and Aβ42 were not statistically significant among the groups (P > 0.05). ConclusionThis study shows that lead can obviously down-regulate the expression of IGF1R and IGFBP3, lead and inhibitor can inhibit the proliferation of cells, promote the tendency of apoptosis, and damage the nervous system.

PSXIII-18 The effect of lead on alkaline phosphatase serum activity in European carp

Abstract The aim of this research is to assess the toxic influence of heavy metals in fish. This study was intended to analyze alkaline phosphatase (AP) serum activity under the influence of various lead concentrations in European carp. AP is involved in the dephosphorylation processes and is an important indicator of liver and skeleton tissue metabolism. When exposed to heavy metals, a change in the activity of this enzyme can be observed. In this experiment 3 groups of fish (European carp) were formed, 10 fish in each group: control group; 1-experimental group – fish were contained in water with 0.06 mg/l lead acetate concentration (upper threshold level than fishery waters permissible exposure limit according to the laws of the Russian Federation); 2-experimental group – fish were contained in water with 0.6 mg/l lead acetate concentration (10 times higher than fishery waters permissible exposure limit according to the laws of the Russian Federation). Exposure time was 4 hours. The blood samplings were taken from heart by syringe and placed in dry test tubes. After samplings centrifugation in non-hemolysed serum samples AP activity was assessed. The study revealed the decreasing trend of AP serum activity by 1.08% (21.89±0.24 IU/l) in 1-experimental group in compare with control group (22.13±0.78 IU/l). In case where the lead acetate concentration were 10 times higher than fishery waters permissible exposure limit were meaningful decreasing of AP activity (P ≤ 0.05) by 66.23% (17.42±0.63 IU/l) accordingly in 2-experimental group in compare with control group. In conclusion, a statistically significant decrease in the AP activity in fish blood serum was found after acetate concentration 10 times higher than the permissible exposure limit in fishery waters, according to the laws of the Russian Federation. We can suppose that the activity of this enzyme is the reason for the inhibitory effect of lead on liver tissue.

Low-level lead exposure promotes hepatic gluconeogenesis and contributes to the elevation of fasting glucose level

BackgroundLead (Pb) is considered an endocrine-disrupting chemical. However, few studies have investigated the effects of low-level Pb exposure on plasma glucose levels. Herein, we aimed to investigate whether low-level Pb exposure causes elevated plasma glucose levels and the possible mechanisms involved. MethodsWe conducted a cross-sectional study of 5747 participants from 16 sites in China. The participants underwent measurements of anthropometric factors, blood lead level (BLL) and fasting plasma glucose (FPG). Wistar rats were exposed to 0.05% Pb through drinking water or fed with a high-fat diet (HFD) for 28 weeks. The relevant parameters of glucose homeostasis, hepatic glucose production (HGP) and gene expression levels of hepatic gluconeogenesis enzymes, including phosphoenolpyruvate carboxy kinase (PEPCK), glucose-6-phosphatase (G6PC) and fructose-1,6-bisphosphatase (FBP1), were measured. In addition, gene expression levels of gluconeogenesis enzymes were also measured in HepG2 cells administered with different concentrations of lead acetate for 24 h. ResultsIn humans, after adjusting for confounders, the odds of having High_FPG (≥5.6 mmol/L) were significantly increased by 25% in the participants in the fourth BLL quartile (OR 1.25, 95% CI 1.05, 1.49). In the animals exposed to 0.05% Pb, FPG, HGP and hepatic gene expression levels of PEPCK, G6PC and FBP1 were increased. In addition, the mRNA expression levels of PEPCK, G6PC and FBP1 in HepG2 cells were also increased in response to Pb exposure. ConclusionsThese findings support the possibility that low-level Pb exposure may increase HGP by affecting key enzymes of hepatic gluconeogenesis, eventually resulting in impaired FPG and hyperglycemia.

Mitochondrial uncoupling protein 2 is regulated through heterogeneous nuclear ribonucleoprotein K in lead exposure models

Synaptic plasticity plays an important role in learning and memory in the developing hippocampus. However, the precise molecular mechanism in lead exposure models remains to be studied. UCP2, an inner mitochondrial anion carrier, regulates synaptic plasticity through uncoupling neurons. And hnRNP K, an RNA binding protein, plays a role in modulating the expression of transcripts coding synaptic plasticity. We aim to investigate whether lead exposure affects UCP2 and hnRNP K expression levels. The Sprague-Dawley rats were exposed to different lead acetate concentrations (0 g/l, 0.5 g/l, 2.0 g/l) during gestational and lactational periods. PC12 cells were also exposed to different lead acetate concentrations (0 μM, 1 μM and 100 μM). We found that the expression levels of UCP2 and hnRNP K had significant declines in the lead exposure rat hippocampus and PC12 cells. Furthermore, the up-regulation of hnRNP K expression level could reverse the expression level of UCP2 in lead exposure models. In conclusion, these results suggest that lead exposure can reduce the expression level of UCP2 which is mediated by decreasing the expression level of hnRNP K.