Objective: To investigate the effect of arsenic and its main metabolites on the apoptosis of human lung adenocarcinoma cell line A549 and the expression of pro-apoptotic genes Bad and Bik. Methods: In October 2020, A549 cells were recovered and cultured, and the cell viability was detected by the cell counting reagent CCK-8 to determine the concentration and time of sodium arsenite exposure to A549. The study was divided into NaAsO(2) exposure groups and metobol: le expoure groups: the metabolite comparison groups were subdivided into the control group, the monomethylarsinic acid exposure group (60 μmol/L) , and the dimethylarsinic acid exposure group (60 μmol/L) ; sodium arsenite dose groups were subdivided into 4 groups: control group (0) , 20, 40, 60 μmol/L sodium arsenite NaAsO(2). Hoechst 33342/propidium iodide double staining (Ho/PI) was used to observe cell apoptosis and real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression levels of Bad and Bik mRNA in cells after exposure. Western blotting was used to detect the protein expressions of Bad, P-Bad-S112, Bik, cleaved Bik and downstream proteins poly ADP-ribose polymerase PARP1 and cytochrome C (Cyt-C) , using spectrophotometry to detect the activity changes of caspase 3, 6, 8, 9. Results: Compared with the control group, the proportion of apoptotic cells in the 20, 40, and 60 μmol/L NaAsO(2) dose groups increased significantly (P<0.01) , and the expression levels of Bad, Bik mRNA, the protein expression levels of Bad, P-Bad-S112, Bik, cleaved Bik, PARP1, Cyt-C were increased (all P<0.05) , and the activities of Caspase 3, 6, 8, and 9 were significantly increased with significantly differences (P<0.05) . Compared with the control group, the expression level of Bad mRNA in the DMA exposure group (1.439±0.173) was increased with a significant difference (P=0.024) , but there was no significant difference in the expression level of Bik mRNA (P=0.788) . There was no significant differences in the expression levels of Bad and Bik mRNA in the poison groups (P=0.085, 0.063) . Compared with the control group, the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to MMA were 0.696±0.023, 0.707±0.014, 0.907±0.031, 1.032±0.016, and there was no significant difference between the two groups (P=0.469, 0.669, 0.859, 0.771) ; the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to DMA were 0.698±0.030, 0.705±0.022, 0.908±0.015, 1.029±0.010, and there was no difference between the two groups (P=0.479, 0.636, 0.803, 0.984) . Conclusion: Sodium arsenite induces the overexpression of Bad and Bik proteins, initiates the negative feedback regulation of phosphorylated Bad and the degradation of Bik, activates the downstream proteins PARP1, Cyt-C and Caspase pathways, and mediates the apoptosis of A549 cells.
A549 Cells ; Adenosine Diphosphate Ribose/pharmacology* ; Apoptosis ; Apoptosis Regulatory Proteins ; Arsenic ; Arsenites ; Cacodylic Acid/pharmacology* ; Caspase 3 ; Caspases/pharmacology* ; Cytochromes c/pharmacology* ; Humans ; Mitochondrial Proteins/pharmacology* ; Poisons ; Propidium/pharmacology* ; RNA, Messenger ; Sincalide/pharmacology* ; Sodium Compounds ; bcl-Associated Death Protein/metabolism*

BACKGROUND: Arsenic is a carcinogenic heavy metal that has a species-dependent health effects and abandoned metal mines are a source of significant arsenic exposure. Therefore, the aims of this study were to analyze urinary arsenic species and their concentration in residents living near abandoned metal mines and to monitor the environmental health effects of abandoned metal mines in Korea. METHODS: This study was performed in 2014 to assess urinary arsenic excretion patterns of residents living near abandoned metal mines in South Korea. Demographic data such as gender, age, mine working history, period of residency, dietary patterns, smoking and alcohol use, and type of potable water consumed were obtaining using a questionnaire. Informed consent was also obtained from all study subjects (n = 119). Urinary arsenic species were quantified using high performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP/MS). RESULTS: The geometric mean of urinary arsenic (sum of dimethylarsinic acid, monomethylarsonic acid, As3+, and As5+) concentration was determined to be 131.98 μg/L (geometric mean; 95% CI, 116.72–149.23) while urinary inorganic arsenic (As3+ and As5+) concentration was 0.81 μg/L (95% CI, 0.53–1.23). 66.3% (n = 79) and 21.8% (n = 26) of these samples exceeded ATSDR reference values for urinary arsenic (>100 μg/L) and inorganic arsenic (>10 μg/L), respectively. Mean urinary arsenic concentrations (geometric mean, GM) were higher in women then in men, and increased with age. Of the five regions evaluated, while four regions had inorganic arsenic concentrations less than 0.40 μg/L, one region showed a significantly higher concentration (GM 15.48 μg/L; 95% CI, 7.51–31.91) which investigates further studies to identify etiological factors. CONCLUSION: We propose that the observed elevation in urinary arsenic concentration in residents living near abandoned metal mines may be due to environmental contamination from the abandoned metal mine. TRIAL REGISTRATION: Not Applicable (We do not have health care intervention on human participants).
Arsenic* ; Cacodylic Acid ; Chromatography, Liquid ; Delivery of Health Care ; Drinking Water ; Environmental Health ; Female ; Humans ; Informed Consent ; Internship and Residency ; Korea* ; Male ; Mass Spectrometry ; Plasma ; Reference Values ; Smoke ; Smoking

OBJECTIVETo investigate the changes in mRNA expression of p53 and related downstream genes in peripheral blood lymphocytes in workers occupationally exposed to arsenic as well as its influencing factors, and to analyze the mechanism of genetic toxicity of arsenic.

METHODSWith cluster random sampling, 79 workers from an arsenic smelting plant were selected as exposure group, and another 24 people without occupational exposure to arsenic were selected as control group. The relative mRNA expression of p53 and related downstream genes in the peripheral blood lymphocytes of the two groups was determined by quantitative realtime PCR. The levels of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in urine were determined by hydride generation-atomic absorption spectrometry.

RESULTSThe exposure group had significantly higher levels of iAs, MMA, and DMA than the control group (P<0.01); the exposure group had significantly higher relative mRNA expression (2(-ΔΔCt)) of p53 and four related downstream genes in peripheral blood lymphocytes than the control group (P<0.05); the relative mRNA expression of p53 and related downstream genes was positively correlated with each other (P<0.01), with a correlation coefficient greater than 0.4; the levels of arsenic compounds in urine were positively correlated with the relative mRNA expression of p53 and some of its downstream genes (P<0.05).

CONCLUSIONThe changes in mRNA expression of p53 and related downstream genes are closely related to the metabolic transformation of inorganic arsenic in workers occupationally exposed to arsenic, and it also plays an important role in genetic toxicity and carcinogenic effect in people exposed to arsenic.

Arsenic ; adverse effects ; urine ; Arsenicals ; urine ; Cacodylic Acid ; urine ; Case-Control Studies ; Humans ; Lymphocytes ; drug effects ; Occupational Exposure ; RNA, Messenger ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

In our previous work, we found that trivalent dimethylarsinous acid (DMA(III)) have high affinity binding to cysteine residue 13 of rat hemoglobin. However, it is still unknown why arsenic intermediate metabolite DMA(III) has high binding affinity for Cysl3 but not for other cysteine residues 93, 140, 111 and 125. In order to better understand the molecular mechanism of DMA(III) with rat hemoglobin, we have done current study. So, SD rats were divided into control and arsenic-treated groups randomly. Arsenic species in lysate of red blood cells were analyzed by HPLC-ICP-MS, and then determined by a hybrid quadrupole TOF MS. In addition, trivalent DMA(III) binds to different cysteine residues in rat hemoglobin alpha and beta chains were also simulated by Molecular Docking. Only Cys13 in alpha chain is able to bind to DMA(III) from the experiment results. Cys13 of alpha chain in rat hemoglobin is a specific binding site for DMA(III), and we found that amino acids compose pockets structure and surround Cys13 (but not other cysteine residues), make DMA(III) much easy to bind cysteine 13. Taken together, the DMA(III) specific binding to Cys13 is related to spatial structure of Cys13.
Animals ; Arsenic ; metabolism ; Binding Sites ; Cacodylic Acid ; analogs & derivatives ; chemistry ; Chromatography, High Pressure Liquid ; Cysteine ; metabolism ; Hemoglobins ; metabolism ; Mass Spectrometry ; Peptide Fragments ; metabolism ; Rats

OBJECTIVES: The purpose of this study was to determine a separation method for each arsenic metabolite in urine by using a high performance liquid chromatography (HPLC)- inductively coupled plasma-mass spectrometer (ICP-MS). METHODS: Separation of the arsenic metabolites was conducted in urine by using a polymeric anion-exchange (Hamilton PRP X-100, 4.6 mm x 150 mm, 5 mum) column on Agilent Technologies 1260 Infinity LC system coupled to Agilent Technologies 7700 series ICP/MS equipment using argon as the plasma gas. RESULTS: All five important arsenic metabolites in urine were separated within 16 minutes in the order of arsenobetaine, arsenite, dimethylarsinate, monomethylarsonate and arsenate with detection limits ranging from 0.15 to 0.27 mug/L (40 muL injection). We used GEQUAS No. 52, the German external quality assessment scheme and standard reference material 2669, National Institute of Standard and Technology, to validate our analyses. CONCLUSIONS: The method for separation of arsenic metabolites in urine was established by using HPLC-ICP-MS. This method contributes to the evaluation of arsenic exposure, health effect assessment and other bio-monitoring studies for arsenic exposure in South Korea.
Argon ; Arsenic* ; Cacodylic Acid ; Chromatography, Liquid ; Environmental Monitoring ; Korea ; Limit of Detection ; Plasma ; Polymers ; Spectrum Analysis*

OBJECTIVES: The purpose of this study was to evaluate the exposure to arsenic in preventive maintenance (PM) engineers in a semiconductor industry by detecting speciated inorganic arsenic metabolites in the urine. METHODS: The exposed group included 8 PM engineers from the clean process area and 13 PM engineers from the ion implantation process area; the non-exposed group consisted of 14 office workers from another company who were not occupationally exposed to arsenic. A spot urine specimen was collected from each participant for the detection and measurement of speciated inorganic arsenic metabolites. Metabolites were separated by high performance liquid chromatography-inductively coupled plasma spectrometry-mass spectrometry. RESULTS: Urinary arsenic metabolite concentrations were 1.73 g/L, 0.76 g/L, 3.45 g/L, 43.65 g/L, and 51.32 g/L for trivalent arsenic (As3+), pentavalent arsenic (As5+), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and total inorganic arsenic metabolites (As3+ + As5+ + MMA + DMA), respectively, in clean process PM engineers. In ion implantation process PM engineers, the concentrations were 1.74 g/L, 0.39 g/L, 3.08 g/L, 23.17 g/L, 28.92 g/L for As3+, As5+, MMA, DMA, and total inorganic arsenic metabolites, respectively. Levels of urinary As3+, As5+, MMA, and total inorganic arsenic metabolites in clean process PM engineers were significantly higher than that in the non-exposed group. Urinary As3+ and As5+ levels in ion implantation process PM engineers were significantly higher than that in non-exposed group. CONCLUSION: Levels of urinary arsenic metabolites in PM engineers from the clean process and ion implantation process areas were higher than that in office workers. For a complete assessment of arsenic exposure in the semiconductor industry, further studies are needed.
Arsenic* ; Cacodylic Acid ; Occupations ; Plants* ; Plasma ; Semiconductors* ; Spectrum Analysis

Arsenic (As) is a well-known human carcinogen and its dietary exposure has been found to be the major route of entry into general population. This study was performed to assess the body levels of As and their associated factors in Korean adults by analyzing total As in urine. Urine and blood samples were collected from 580 adults aged 20 years and older, who had not been exposed to As occupationally. Demographic information was collected with the help of a standard questionnaire, including age, smoking, alcohol intake, job profiles, and diet consumed in the last 24 hrs of the study. Total As, sum of As(III), As(V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), in urine was determined using atomic absorption spectrometer involving hydride generation method. The geometric mean concentration of total As in urine was 7.10 microg/L. Urine As was significantly higher in men (7.63 microg/L) than in women (6.75 microg/L). Age, smoking, alcohol consumption, and job profiles of study subjects did not significantly affect the concentration of As in urine. No significant relationship was observed between body mass index (BMI), Fe, and total cholesterol in serum and urinary As. Urine As level was positively correlated with seaweeds, fishes & shellfishes, and grain intake. A negative correlation between urinary As level and HDL-cholesterol in serum and meat intake was observed. Overall, these results suggest that urinary As concentration could be affected by seafood consumption. Therefore, people who frequently consume seafood and grain need to be monitored for chronic dietary As exposure.
Absorption ; Adult ; Aged ; Alcohol Drinking ; Arsenic ; Arsenicals ; Body Mass Index ; Cacodylic Acid ; Edible Grain ; Cholesterol ; Diet ; Female ; Fishes ; Humans ; Life Style ; Male ; Meat ; Occupations ; Surveys and Questionnaires ; Seafood ; Shellfish ; Smoke ; Smoking

Changes in the testis interstitium from birth to adulthood were studied in New Zealand white rabbits of 1, 7, 21, 35, 49, 70, 105, 147, 196, and 252 days (n=8 per group) of age. Testes of rabbits were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 microm sections stained with methylene blueazure II, qualitative and quantitative (stereological) morphological studies were performed. Sperm production was measured by routine technique. The volume density of the interstitium represents 66.3% of the testicular parenchyma at day 1. Adult Leydig cells initially detected at day 7 (0.001%), increased progressively to reach a volume density of 2.6% by day 252. The absolute volume of mesenchymal cells, endothelial cells, pericytes, and myoid cells increased from birth to 252 days. The number of endothelial cells, pericytes, and myoid cells per testis increased gradually with age. The absolute numbers of adult Leydig cells and mesenchymal cells per testis increased linearly from birth to 252 days. The rate of production of adult Leydig cells was greater than that of mesenchymal cells in the postnatal rabbit testis through 252 days. The average volume of a mesenchymal cell increased from day 1 to day 70 and declined thereafter; the highest value was at day 70. Total sperm production and daily sperm production per testis increased significantly from 105 to 252 days of age. These results clarified the pattern of changes in the testis interstitium in rabbits from birth to adulthood and correlation these events with spermatogenesis.
Adult ; Cacodylic Acid ; Endothelial Cells ; Glutaral ; Humans ; Leydig Cells ; Male ; Parturition ; Perfusion ; Pericytes ; Rabbits ; Spermatogenesis ; Spermatozoa ; Testis

Changes in the testis interstitium from birth to adulthood were studied in New Zealand white rabbits of 1, 7, 21, 35, 49, 70, 105, 147, 196, and 252 days (n=8 per group) of age. Testes of rabbits were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 microm sections stained with methylene blueazure II, qualitative and quantitative (stereological) morphological studies were performed. Sperm production was measured by routine technique. The volume density of the interstitium represents 66.3% of the testicular parenchyma at day 1. Adult Leydig cells initially detected at day 7 (0.001%), increased progressively to reach a volume density of 2.6% by day 252. The absolute volume of mesenchymal cells, endothelial cells, pericytes, and myoid cells increased from birth to 252 days. The number of endothelial cells, pericytes, and myoid cells per testis increased gradually with age. The absolute numbers of adult Leydig cells and mesenchymal cells per testis increased linearly from birth to 252 days. The rate of production of adult Leydig cells was greater than that of mesenchymal cells in the postnatal rabbit testis through 252 days. The average volume of a mesenchymal cell increased from day 1 to day 70 and declined thereafter; the highest value was at day 70. Total sperm production and daily sperm production per testis increased significantly from 105 to 252 days of age. These results clarified the pattern of changes in the testis interstitium in rabbits from birth to adulthood and correlation these events with spermatogenesis.
Adult ; Cacodylic Acid ; Endothelial Cells ; Glutaral ; Humans ; Leydig Cells ; Male ; Parturition ; Perfusion ; Pericytes ; Rabbits ; Spermatogenesis ; Spermatozoa ; Testis

The present study was conducted to investigate the influence of hemicastration and age at hemicastraion on the subsequent Leydig cell morphology and function of male rats. Sprague Dawley rats were left intact or hemicastrated at 20, 30, 40, 50, or 60 days of age (n=18 rats per group). At 100 days of age, all rats were sacrificed. Testes were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 micrometer sections stained with methylene blue, qualitative and quantitative morphological studies were performed. Testis incubations were used to determine lutenizing hormone (LH; 100 ng/mL) stimulated testosterone secretory capacity per testis in vitro. Testosterone levels in the incubation medium, and testosterone and LH levels in serum of these six groups of rats were determined by radioimmunoassay. Body and testis weights were not changed by hemicastration between experimental and control groups. Volume density of seminiferous tubules, interstitium, and Leydig cells was not significantly affected by hemicastration. Absolute volume of seminiferous and interstitium was significantly increased in unilaterally castrated rats at 20, 30 and 40 days of age compared to control. Significant increases in the total number of Leydig cells per testis occurred in rats hemicastrated at 20, 30, 40 and 50 days of age compared to control. A significant increase in average volume of a Leydig cell was noted in the hemicastrated rats at 30 and 40 days compared to intact rats of the same age but was significantly decreased at 60 days of age. Serum testosterone levels and LH-stimulated testosterone production per testis were significantly (P<0.05) increased in the hemicastrated rats at 30 and 40 days. In summary, when rats were unilaterally castrated at 20, 30, 40, 50, and 60 days of age, those rats hemicastrated at 30 and 40 days showed compensatory hypertrophy/hypersecretion of Leydig cells when killed at 100 days of age. Especially, these data suggested that compensatory hypertrophy/hypersecretion of Leydig cells in rats hemicastrated around the time of puberty occurs in the remaining testis.
Animals ; Cacodylic Acid ; Glutaral ; Humans ; Leydig Cells ; Male ; Methylene Blue ; Perfusion ; Puberty ; Radioimmunoassay ; Rats ; Rats, Sprague-Dawley ; Seminiferous Tubules ; Testis ; Testosterone ; Weights and Measures