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Backgroud Beta-cypermethrin and emamectin benzoate are widely used for the prevention and control of pests in the greenhouse planting industry, and their combined exposure may increase the accumulation of beta-cypermethrin and emamectin benzoate in organisms and affect human health. Objective Based on the changes in reproductive hormone levels in the hypothalamic-pituitary-ovarian (HPO) axis, to investigate the effect of combined exposure to beta-cypermethrin and emamectin benzoate on the estrous cycle of female mice. Methods Twenty-four healthy adult SD rats were randomly divided into a blank control group, a beta-cypermethrin group (Beta-CYP, 53 mg·m−3), an emamectin benzoate group (EMB, 8 mg·m−3), and a beta-cypermethrin and emamectin benzoate combined exposure group (Beta-CYP+EMB, Beta-CYP 53 mg·m−3 + EMB 8 mg·m−3). Six rats in each group were exposed to the designed treatment protocol by aerosol inhalation 6 d a week for 13 weeks. The general condition of the rats was observed in real time during the treatment. From the 12th week of exposure, a 10-day reproductive tract smear was performed on the rats to observe the estrous cycle. The rats were neutralized on the second day after the end of the treatment protocol, and the ovarian tissues were stained with HE to observe histopathological changes. Serum levels of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were measured by ELISA. Experimental results were expressed as mean ± standard deviation (\begin{document}$ \overline{x}\pm s $\end{document}). One-way ANOVA was used for comparison among groups, and LSD test for pairwise comparison between groups. The significance level was α=0.05. Results After four weeks of the treatment protocol, the rats in the Beta-CYP group and the Beta-CYP+EMB group continued to be hyperactive and irritable, while the EMB group showed symptoms of mental disorder, decreased activity, and slow response. On the 90th day of the treatment protocol, the body weight of rats in the control group increased to (314.51±2.44) g, and that in the Beta-CYP+EMB group only increased to (253.47±1.50) g. There was no abnormal cellular morphology in the control group; however, small deeply stained nuclei appeared in the Beta-CYP group, the EMB group, and the Beta-CYP+EMB group, and abnormal morphological development of keratinized epithelial cells in the Beta-CYP+EMB group was found. The estrous cycle of rats in the control group was (97.83±4.17) h, and compared with the control group, the estrous cycles of rats in the Beta-CYP group, the EMB group, and the Beta-CYP+EMB group were prolonged to (134.33±7.53) h, (126.50±5.28) h, and (156.00±6.66) h, respectively. The results of ANOVA showed that the numbers of leukocytes (527.17±15.83), keratinized epithelial cells (35.67±4.32), and non-keratinized epithelial cells (70.50±4.51) in the vaginal smears during diestrus in the Beta-CYP+EMB group were significantly lower than those in the control group (752.50±28.89, 50.50±2.74, 101.33±7.92) (P<0.001). The hormone levels of GnRH and FSH in the control group were (5.13±0.59) and (0.76±0.09) IU·L−1 respectively, while the levels in the Beta-CYP+EMB group were increased to (16.86±0.59) and (3.80±0.19) IU·L−1 respectively (P<0.05). The levels of LH and E2 in the control group were (12.93±0.81) IU·L−1 and (22.23±1.44) pmol·L−1 respectively, and the levels in the Beta-CYP+EMB group were decreased to (5.63±0.41) IU·L−1 and (10.45±0.78) pmol·L−1 respectively (P<0.05). Conclusion The combined exposure to beta-cypermethrin and emamectin benzoate may ultimately affect the estrous cycle of female rats by interfering with the secretion of reproductive hormones involved in the HPO axis.
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Ambient fine particulate matter (PM2.5) is particulate matter with an aerodynamic diameter less than 2.5 μm, and has an extremely wide range of sources. It affects the environmental quality in many cities and regions around the world, and associates with lots of negative effects on public health. E-cigarettes, a group of products that atomize e-liquid by an atomizer and then deliver nicotine and/or other substances to the respiratory system, have been introduced as smoking cessation products or replacement of tobacco cigarettes in recent years. The usage rate of e-cigarettes has grown rapidly all over the world. When these two pollutants coexist in the same atmosphere, they would induce certain adverse health effects not only on the e-cigarette users, but also on the people around them. Besides causing cardiopulmonary toxicity, the co-existing pollutants may associate with higher risks of developmental toxicity and carcinogenicity. In addition, the combined exposure may be related with the occurrence of depression. Therefore, there is an urgent need to conduct studies on the toxic potential of the combined exposure to PM2.5 and e-cigarettes, which is also important for the evaluation and control of the atmospheric compound pollution associated health risk. This paper reviewed the current situation of PM2.5 pollution and e-cigarettes use, introduced the epidemiological studies of PM2.5 and e-cigarette combined exposure, their toxic effects in vivo and in vitro, and possible mechanisms, aiming to provide a reference for subsequent toxicity studies.
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Objective @#To investigate the combined effects of triclosan（TCS）and PCB153 on the activity of superoxide dismutase（SOD）and the concentration of malondialdehyde（MDA）in zebrafish liver.@*Methods @#Adult zebrafish were exposed to a series of concentrations of TCS,and the mortality in each group was observed and recorded during the acute toxicity test process. The concentrations in subsequent combined exposure experiments were arranged on the basis of the 96 h-LC50. The factorial design was used to determine the concentrations of combined exposure groups between TCS（0,0.125,0.5 μmol/L）and PCB153（0,0.05,0.2 μmol/L）. After 5,10 and 14 days of exposure,the zebrafish livers were dissected and frozen in each group. The potential interactions of these two compounds were analyzed according to the results of the SOD and MDA.@*Results @#The 96 h-LC50 of TCS exposed to adult zebrafish was 2.64 μmol/L（95%CI：2.37-2.89 μmol/L）. After 5 days of exposure,combined exposure to 0.5 μmol/L TCS+0.2 μmol/L PCB153 caused lower liver SOD activities than single exposure groups and the control group（P<0.05）. After 10 days of exposure,combined exposure to 0.125 μmol/L TCS+0.05 μmol/L PCB153,0.5 μmol/L TCS+0.05 μmol/L PCB153 caused lower liver SOD activities than single exposure groups and the control group（P<0.05）. After 14 days of exposure,combined exposure to 0.5 μmol/L TCS+0.05 μmol/L PCB153,0.5 μmol/L TCS+0.2 μmol/L PCB153 caused higher liver SOD activities than single exposure groups and the control group（P<0.05）. There was an interactive effect between TCS and PCB153 on the liver SOD activity in zebrafish（P<0.05）. There was no significant effect of MDA content in each group.@*Conclusion @#Combined exposure to TCS and PCB153 could enhance （inhibit first） the liver SOD activities in zebrafish,and the interaction was synergistic.
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OBJECTIVE: To investigate the effect and mechanism of lead exposure on hypothalamic inflammatory factors in mice fed with high-fat diet. METHODS: Specific pathogen free healthy male Kunming mice were randomly divided into control group, high-fat diet group, lead exposure group, and combined exposure group, with 8 rats in each group. The control group and the lead exposure group were given regular diet, while high-fat diet group and combined exposure group were given high-fat diet. The lead exposure group and combined exposure group were given water with 250 mg/L lead acetate. The control group and high-fat diet group were given double distilled water. Continuous lead exposure was given for 9 weeks, 7 days per week. Body weights of the mice were measured every other week. After 9 weeks of exposure, the behavioral changes of mice were detected by open field test. The levels of triglyceride(TG), low density lipoprotein(LDL) and high density lipoprotein(HDL) in serum were detected by microplate reader. Western blotting was used to detect the relative protein expression of interleukin(IL)-1β, IL-6, IL-17 A, IL-22, tumor necrosis factor-α(TNF-α) and transforming growth factor-β(TGF-β) in the hypothalamus of mice. The relative expression of mRNA of IL-1β, IL-6, IL-17 A and TNF-α mRNA was detected by real-time fluorescence quantitative polymerase chain reaction. RESULTS: Beginning from the first week, the body weights of mice in the high-fat diet group and the combined exposure group were higher than that in the control group and the lead exposure group(P<0.05). The numbers of standing in the lead exposure group and the combined exposure group were lower than that in the control group and the high-fat diet group(P<0.05). The distances of central area activity in the high-fat diet group, the lead exposure group and the combined exposure group were lower than that in the control group(P<0.05). The total distances in the high-fat diet group and the combined exposure group were lower than that in the control group(P<0.05). The serum levels of TG and LDL in the combined exposure group increased(P<0.05), and the HDL level decreased(P<0.05), when compared with the control group and the lead exposure group. The relative protein expression of IL-1β, IL-6, IL-17 A and IL-22 in the hypothalamus of the high-fat diet group and lead exposure group was higher than those of the control group(P<0.05). The relative protein expression of TNF-α and TGF-β in the hypothalamus of the lead exposure group was higher than that in the control group(P<0.05). The relative protein expression of IL-1β, IL-6, IL-17 A, TGF-β in the hypothalamus of the combined exposure group was higher than the other 3 groups(P<0.05). The relative protein expression of IL-22 in the hypothalamus of the combined exposure group was higher than that of the control group(P<0.05), while the relative protein expression of TNF-α was higher than that of the control group and the high-fat diet group(P<0.05). The relative expression of IL-1β, IL-6, IL-17 A, and TNF-α mRNA in the hypothalamus of the high-fat diet group, the lead exposure group and the combined exposure group was higher than that in the control group(P<0.05). The above indicators of mice in the lead exposure group were higher than that in the high-fat diet group(P<0.05). The above indicators of mice in the combined exposure group were higher than those in the high-fat diet group and the lead exposure group(P<0.05). CONCLUSION: Lead exposure can promote neurobehavioral changes and hypothalamic inflammatory damage in high-fat diet mice. IL-1β, IL-6, IL-17 A, TGF-β and TNF-α might involve in the process of synergistic effect of lead and high-fat diet exposure on inflammatory hypothalamic injury.
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BACKGROUND: We evaluated the association of blood pressure (BP) with blood levels of cadmium, lead, and cadmium and lead together (cadmium + lead) in a representative sample of adolescents from Korea. METHODS: We used 2010–2016 data from the Korean National Health and Nutrition Examination Survey. This cross-sectional study enrolled adolescents aged at 10–18 years-old who completed a health examination survey and had blood measurements of lead and cadmium. The association of adjusted mean differences in diastolic and systolic BP with doubling of blood lead and cadmium were estimated by regression of BP against log2-transformed blood metals and their quartiles after covariate adjustment. Adjusted odds ratio for prehypertension were calculated for log2-transformed blood levels of lead and cadmium and their quartiles. RESULTS: Our analysis of adolescents in Korea indicated that blood levels of lead and cadmium were not significantly associated with increased BP or risk of prehypertension. However, the cadmium + lead level was associated with prehypertension. Previous studies showed that blood levels of lead and cadmium were associated with increased BP and risk of hypertension in adult populations. We found no such association in Korean adolescents. CONCLUSION: We found that the cadmium + lead level was associated with prehypertension. The differences between adults and adolescents are because adolescents generally have lower levels of these blood metals or because adolescents only rarely have hypertension.
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Adolescent , Adult , Humans , Blood Pressure , Cadmium , Cross-Sectional Studies , Hypertension , Korea , Metals , Nutrition Surveys , Odds Ratio , PrehypertensionABSTRACT
OBJECTIVE: To observe the hepatic injury induced by combined exposure to diethylhexyl phthalate( DEHP) and bisphenol A( BPA) in rats and explore the mechanism of oxidative stress. METHODS: Thirty-two specific pathogen free healthy male SD rats were randomly divided into control group,DEHP(750 mg/kg body weight) group,BPA(100 mg/kg body weight) group and combined exposure group,with 8 rats in each group. The rats were gavaged once per day,7 days per week,for 6 weeks. The changes of liver organ coefficient and histopathology were observed. The activities of superoxide dismutase( SOD), glutathione peroxidase( GSH-Px) and the levels of hydrogen peroxide( H2 O2),malondialdehyde( MDA) were detected by spectrophotometry. The relative mRNA expression of antioxidant gene nuclear factor erythroid-2 related factor 2( Nrf2),heme oxygenase-1( HO-1),glutamate cysteine ligase catalytic subunit( Gclc),thioredoxin reductase( Txnrd),superoxide dismutase 3( Sod3) and glutathione peroxidase 1( Gpx1) in liver tissue were examined by real-time fluorescent quantitative polymerase chain reaction. RESULTS: The body weight of DEHP exposure group was lower than that of control group from the beginning of the 2 nd week( P < 0. 05),and the body weight of combined exposure group was lower than control group from the beginning of the 3 rd week( P < 0. 05). The liver mass and organ coefficients in DEHP group and combined exposure group were significantly higher than that of control group( P <0. 05). The results of pathology examination showed that there was necrosis of liver cells in DEHP group,vacuolar degeneration in cytoplasm of BPA group,and severe inflammatory cell infiltration in combined exposure group. The activity of SOD and GSH-Px of each exposure group was reduced( P < 0. 05),the H2 O2 level of each exposure group was increased(P < 0. 05),meanwhile the MDA level in the liver tissue of the BPA group and the combined exposure group increased compared with the control group( P < 0. 05). The relative mRNA expression of Nrf2,HO-1 and Gpx1 in each exposure group were decreased( P < 0. 05),the relative mRNA expression of Gclc,Txnrd and Sod3 in DEHP group and mixed exposure group were decreased compared with the control group( P < 0. 05). The relative mRNA expression of Nrf2,HO-1,Gclc,Txnrd and Sod3 in combined exposure group were decreased compared with the BPA group( P < 0. 05).CONCLUSION: Under the conditions of this study,DEHP and BPA alone or in combination could cause hepatic injury. The combined effect was greater than single effect. The effect of DEHP was greater than that of BPA. The liver injury induced by DEHP and BPA was related to Nrf2 signaling pathway.
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SOD.Conclusion Mn,Cd and Mn-Cd combined exposure has a significant inhabitation on cowpea growth with Cd alone being heaviest and Mn lowest.The physiological indicators show that when combined pollution occurs,an antagonistic effect between Mn and Cd is exhibited.