Objective: To explore the effect of lead exposure on the neurobehavior and gut microbiota community structure in mice. Methods: In August 2019, 64 C57BL/6 mice were randomly divided into 4 groups: control group (0 ppm) , low lead exposure group (20 mg/l) , medium lead exposure group (100 mg/l) and high lead exposure group (500 mg/l) . During the experiment, they were free to eat and drink. The drinking water of the lead exposure group was mixed with lead acetate, and sodium acetate was added in the control group. After 10 weeks of exposure, the Morris water maze was used to test the learning and memory ability of each group of mice, and then they were sacrificed for sampling. ICP-MS was used to detect lead content in whole blood and brain tissue. ELISA was used to determine the level of IL-1β in mouse serum. 16S rRNA sequencing was used to detect the structural diversity of the intestinal flora in feces, and then the correlation between the flora and behavior indicators was analyzed. Results: In the Morris water maze experiment, compared with the control group, there was no significant difference in the body weight and swimming speed of the mice in the lead exposure groups. The escape latency of the mice in the 100 mg/l and 500 mg/l dose groups was prolonged, and the number of platform crossings decreased (P<0.05) ; meanwhile, the staying time of the mice in the 500 mg/l Pb-treated group in the target quadrant was lower than that of the control group, and the difference was statistically significant (P<0.05) . Compared with the control group, the blood lead content of the mice in each lead exposure group was significantly increased, and the brain lead content of mice in the 500 mg/l dose group was significantly elevated (P<0.05) . The serum IL-1β levels of mice in each lead exposure group were higher than those of the control group (P<0.05) . At the phylum level, the relative abundance of the Proteobacteria phylum in all of Pb-treated groups was significantly increased (P<0.05) ; at the genus level, Allobaculum, Desulfovibrio, Lachnospiraceae_NK4A136_group, Turicibacter and Ureaplasma were significantly increased (P<0.05) . Among them. The relative abundance of Desuffaoibrio, Turici bacter, and Ureaplasma was negatively correlated with the residence time of mice in the quadrant of the platform (r=-0.32, -0.29, -0.44, P<0.05) . Conclusion: Lead exposure induced learning and memory impairments in mice, which may be related to the disturbance of the gut microbiota.
Animals ; Gastrointestinal Microbiome ; Lead/toxicity* ; Maze Learning ; Memory Disorders ; Mice ; Mice, Inbred C57BL ; RNA, Ribosomal, 16S/genetics*

Leech has a good anticoagulant activity and is one of the raw materials for treatment of many cardiovascular and cerebrovascular diseases. This study was based on in vitro anticoagulant experiments( APTT and PT) to investigate the effects of lead contamination on the anticoagulant effect of leech. At present,the Hirudo circulating in the market are dominated by Whitmania pigra,therefore Wh. pigra were cultivated under a different lead pollution for 50 days. Then,the effects of Wh. pigra extract,extracting from different cultivating environment,on activated partial thrombin time( APTT) and prothrombin time( PT) were determined by automatic coagulation instrument. The results showed that the Wh. pigra extract significantly prolonged the APTT compared with the saline group.The APTT of the lead-high residual Wh. pigra was shorter than that of the blank Wh. pigra. The Wh. pigra extracts from different treatment groups had little effect on PT. The results showed that the lead residue in the Wh. pigra increased with the increase of lead in the cultured soil,the lead residual of the Pb-H group was( 10. 66±2. 79) mg·kg~(-1),which exceeded the lead limit specified in the 2015 edition of the Chinese Pharmacopoeia. The results indicated that growth environment pollution is one of the important factors causing excessive lead in Wh. pigra. Lead pollution will reduce the anticoagulant effect of Wh. pigra and affect its clinical efficacy.
Animals ; Anticoagulants ; Biological Products/pharmacology* ; Blood Coagulation ; Environmental Pollution ; Lead/toxicity* ; Leeches/drug effects* ; Prothrombin Time ; Thrombin Time

Heavy metal is one of pollutants existed widely in the environment, its relationship with cardiovascular disease has attracted more and more attention. In this review, the concentrations of heavy metals, including lead, cadium and asenic, in the body from several national surveillance networks and the epidemiological studies on the effects of the exposure of three heavy metals on cardiovascular system were summarized. It is suggested to strengthen nationwide surveillance for body concentrations of heavy metals in general population in order to provide baseline data for quantitative evaluation of the risk of heavy metal exposure on cardiovascular disease.
Cadmium ; Cardiovascular Diseases/chemically induced* ; Environmental Exposure/adverse effects* ; Environmental Pollutants/toxicity* ; Epidemiologic Studies ; Humans ; Lead/toxicity* ; Metals, Heavy/toxicity* ; Neoplasms ; Research/trends*

We aimed to investigate the short-term correlation between blood lead levels and oxidative stress generation in coal miners. The study involved 94 male coal miners from the Velenje Coal mine, arranged into four groups: three groups according to the number of consecutive working days, and a fourth control group. Miners who worked for three consecutive days had higher blood levels of lead and 8-isoprostane than the control group (P < 0.001). Correlation between lead and 8-isoprostane was of medium strength (r = 0.512, P < 0.001). Short-term lead environmental exposure can potentially harmful and should be considered when formulating improvements in working processes.
Adult ; Coal Mining ; Environmental Pollutants ; toxicity ; Humans ; Isoprostanes ; blood ; Lead ; blood ; toxicity ; Male ; Occupational Exposure ; Oxidative Stress ; drug effects

Lead exposure is a known potential risk factor for neurodegenerative diseases such as Alzheimer's disease (AD). Exposure to lead during the critical phase of brain development has been linked with mental retardation and hypophrenia in later life. This study was aimed to investigate the effects of lead exposure of pregnant mice on the expressions of insulin-degrading enzyme (IDE) and nerve growth factor (NGF) in the hippocampus of their offspring. Blood samples were collected from the tail vein, and after anesthetizing the pups, the brain was excised on postnatal day 21. Lead concentrations were determined by graphite furnace atomic absorption spectrophotometry, and the expressions of IDE and NGF were determined by immunohistochemistry and Western blotting. Results showed that the reduction in IDE and NGF expression in the hippocampus of pups might be associated with impairment of learning and memory and dementia induced by maternal lead exposure during pregnancy and lactation.
Animals ; Down-Regulation ; Female ; Gene Expression Regulation, Developmental ; drug effects ; Gene Expression Regulation, Enzymologic ; drug effects ; Hippocampus ; drug effects ; growth & development ; metabolism ; Insulysin ; genetics ; metabolism ; Lead ; toxicity ; Mice ; Pregnancy ; Prenatal Exposure Delayed Effects ; chemically induced

OBJECTIVETo study the effects of embryonic lead exposure on food intake and bowel movement in offspring rats and possible mechanisms.

METHODSSprague-Dawley rats were given 0.1% (low-dose lead exposure group) or 0.2% (high-dose lead exposure group) lead acetate freely during pregnancy to establish an animal model of embryonic lead exposure. A blank control group was also established. The male offspring rats were enrolled in the study, and 10 male offspring rats from each group were selected to observe the changes in food intake, bowel movement, gastric emptying, intestine propulsion, and pathological inflammatory response in the gastric mucosa. Eight offspring rats were selected from each group, and electron microscopy and immunohistochemistry were used to observe the changes in the ultrastructure of jejunal microvilli and cell junction and the expression of cholecystokinin-8 (CCK-8) and motilin (MTL) in the feeding center, in order to reveal the possible mechanisms for abnormal gastrointestinal motility in offspring rats induced by embryonic lead exposure.

RESULTSCompared with the control group, the low- and high-dose lead exposure groups had a significant reduction in daily food intake, a significant increase in water content of feces, a significant reduction in fecal pellet weight, and a significant increase in small intestine propulsion (P<0.05). The high-dose lead exposure group had a significant reduction in gastric emptying ability compared with the control group (P<0.05). Compared with the control group, the lead exposure groups had significantly greater pathological inflammatory changes in the gastric mucosa (P<0.05), significant reductions in the number and length of the jejunal microvilli and the number of epithelial desmosome junctions (P<0.05), a significant increase in the macula densa gap (P<0.05), and significant increases in the expression of MTL and CCK-8 in the feeding center (P<0.05), in a dose-dependent manner.

CONCLUSIONSThe degree of gastrointestinal structural injury and expression levels of MTL and CCK-8 in the feeding center are lead dose-dependent, which may be important mechanisms for changes in food intake, bowel movement, and digestive functions in offspring rats induced by embryonic lead exposure.

Animals ; Defecation ; drug effects ; Eating ; drug effects ; Female ; Fetus ; drug effects ; Gastric Emptying ; drug effects ; Jejunum ; drug effects ; pathology ; Lead ; toxicity ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo explore the effects of embryonic lead exposure on motor function and balance ability in offspring rats and the possible mechanisms.

METHODSAn animal model of embryonic lead exposure was prepared with the use of pregnant Sprague-Dawley rats freely drinking 0.1% (low-dose group, LG) or 0.2% (high-dose group, HG) lead acetate solution. A normal control group (NG) was also set. The male offspring rats of these pregnant rats were included in the study, consisting of 12 rats in the NG group, 10 rats in the LG group, and 9 rats in the HG group. The offspring rats' motor function and balance ability were evaluated using body turning test and coat hanger test. Eight rats were randomly selected from each group, and immunohistochemistry and Timm's staining were employed to measure the expression of c-Fos and mossy fiber sprouting (MFS) in the hippocampus.

RESULTSThe HG group had a significantly longer body turning time than the NG and LG groups (P<0.05), and the LG group had a significantly longer body turning time than the NG group (P<0.05). The HG group had a significantly lower score of balance ability than the NG and LG groups (P<0.05), and the LG group had a significantly lower score of balance ability than the NG group (P<0.05). The area percentage of c-Fos-positive neurons in the hippocampal CA1 region was significantly higher in the HG group than in the other two groups (P<0.05), and it was significantly higher in the LG group than in the NG group (P<0.05). The semi-quantitative scores of MFS in the hippocampal CA3 region and dentate gyrus were significantly higher in the HG group than in the other two groups (P<0.05), and they were significantly higher in the LG group than in the NG group (P<0.05).

CONCLUSIONSEmbryonic lead exposure could impair the offspring rats' motor function and balance ability. These changes may be related to increased c-Fos expression in the hippocampal CA3 region and abnormal MFS in the hippocampal CA3 region and dentate gyrus.

Animals ; Female ; Fetus ; drug effects ; Hippocampus ; chemistry ; drug effects ; Lead ; toxicity ; Male ; Mossy Fibers, Hippocampal ; drug effects ; Motor Activity ; drug effects ; Postural Balance ; drug effects ; Pregnancy ; Proto-Oncogene Proteins c-fos ; analysis ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the influence of lead exposure in rats during the developmental stage on the expression of leptin in plasma, cerebrospinal fluid, and hippocampus, as well as investigating whether leptin is associated with the mechanism of cognitive impairment induced by lead exposure.

METHODSThe rat model of cognitive impairment after chronic lead exposure was established by adding lead acetate into drinking water. According to the concentration of lead acetate in drinking water, the rats were divided into control (0 ppm), low-lead (50 ppm), medium-lead (200 ppm), and high-lead groups (1 000 ppm), with 16 rats in each group. Atomic absorption spectrometry was used to measure the content of lead in the plasma, cerebrospinal fluid and hippocampus. ELISA was used to measure the level of leptin in the plasma and cerebrospinal fluid. Immunohistochemistry was used to observe the distribution of leptin protein in the hippocampus. Western blot was used for relative quantification of leptin proteins in the hippocampus.

RESULTSCompared with the control group, the lead exposure groups showed significant increases in the content of lead in blood, cerebrospinal fluid, and hippocampus (P<0.01), as well as significant reductions in the levels of leptin in plasma and cerebrospinal fluid (P<0.05). The results of immunohistochemical staining showed that leptin was mainly distributed in the cytoplasm of pyramidal neurons in the hippocampal CA region. The results of Western blot showed that compared with the control group, the three lead exposure groups showed a slight increase in the protein expression of leptin in the hippocampus (P>0.05).

CONCLUSIONSLead exposure can reduce the levels of leptin in plasma and cerebrospinal fluid in rats, which may be associated with the mechanism of cognitive impairment induced by lead exposure.

Animals ; Apoptosis ; drug effects ; Cognition ; drug effects ; Female ; Hippocampus ; chemistry ; drug effects ; pathology ; Lead ; blood ; toxicity ; Leptin ; analysis ; blood ; cerebrospinal fluid ; Male ; Rats ; Rats, Sprague-Dawley

Lead (Pb), mercury (Hg), and cadmium (Cd) are common heavy metal toxins and cause toxicological renal effects at high levels, but the relevance of low-level environmental exposures in the general population is controversial. A total of 1,797 adults who participated in the KNHANES (a cross-sectional nationally representative survey in Korea) were examined, and 128 of them (7.1%) had chronic kidney disease (CKD). Our study assessed the association between Pb, Hg, Cd exposure, and CKD. Blood Pb and Cd levels were correlated with CKD in univariate logistic regression model. However, these environmental heavy metals were not associated with CKD after adjustment for age, sex, BMI, smoking, hyperlipidemia, hypertension, diabetes, and these metals in multivariate logistic regression models. We stratified the analysis according to hypertension or diabetes. In the adults with hypertension or diabetes, CKD had a significant association with elevated blood Cd after adjustment, but no association was present with blood Pb and Hg. The corresponding odds ratio [OR] of Cd for CKD were 1.52 (95% confidence interval [CI], 1.05-2.19, P=0.026) in adults with hypertension and 1.92 (95% CI, 1.14-3.25, P=0.014) in adults with diabetes. Environmental low level of Pb, Hg, Cd exposure in the general population was not associated with CKD. However, Cd exposure was associated with CKD, especially in adults with hypertension or diabetes. This finding suggests that environmental low Cd exposure may be a contributor to the risk of CKD in adults with hypertension or diabetes.
Adult ; Cadmium/blood/*toxicity ; Cross-Sectional Studies ; Diabetes Mellitus/chemically induced/epidemiology ; *Environmental Exposure ; Female ; Humans ; Hypertension/chemically induced/epidemiology ; Kidney/drug effects/pathology ; Lead/blood/*toxicity ; Male ; Mercury/blood/*toxicity ; Metals, Heavy/*poisoning ; Middle Aged ; Nutrition Surveys ; Poisoning/*epidemiology ; Renal Insufficiency, Chronic/*epidemiology ; Republic of Korea ; Surveys and Questionnaires ; Young Adult

OBJECTIVETo investigate the effects of nano-lead exposure on learning and memory and iron homeostasis in the brain of the offspring rats on postnatal day 21 (PND21) and postnatal day 42 (PND42).

METHODSTwenty adult pregnant female Sprague-Dawley rats were randomly divided into control group and nano-lead group. Rats in the nano-lead group were orally administrated 10 mg/kg nano-lead, while rats in the control group were administrated an equal volume of normal saline until PND21. On PND21, the offspring rats were weaned and given the same treatment as the pregnant rats until 42 days after birth. The learning and memory ability of offspring rats on PND21 and PND42 was evaluated by Morris water maze test. The hippocampus and cortex s amples of offspring rats on PND21 and PND42 were collected to determine iron and lead levels in the hippocampus and cortex by inductively coupled plasma-mass spectrometry. The distributions of iron in the hippocampus and cortex were observed by Perl's iron staining. The expression levels of ferritin, ferroportin 1 (FPN1), hephaestin (HP), and ceruloplasmin (CP) were measured by enzyme-linked immunosorbent assay.

RESULTSAfter nano-lead exposure, the iron content in the cortex of offspring rats on PND21 and PND42 in the nano-lead group was significantly higher than those in the control group (32.63 ± 6.03 µg/g vs 27.04 ± 5.82 µg/g, P<0.05; 46.20 ±10.60 µg/g vs 36.61 ± 10.2µg/g, P<0.05). The iron content in the hippocampus of offspring rats on PND42 in the nano-lead group was significantly higher than that in the control group (56.9 ± 4.37µg/g vs 37.71 ± 6.92µg/g, P<0.05). The Perl's staining showed massive iron deposition in the cortex and hippocampus in the nano-lead group. FPNl level in the cotfex of offspring rats on PND21 in the nano-lead group was significantly lower than that in the control group (3.64 ± 0.23 ng/g vs 4.99 ± 0.95 ng/g, P<0.05). FPN1 level in the hippocampus of offspring rats on PND42 in the nano-lead group was significantly lower than that in the control group (2.28 ± 0.51 ng/g vs 3.69 ± 0.69 ng/g, P<0.05). The escape latencies of offspring rats on PND21 and PND42 in the nano-lead group were longer than those in the control group (15.54 ± 2.89 s vs 9.01 ± 4.66 s; 6.16 ± 1.42 s vs 4.26 ± 1.51 s). The numbers of platform crossings of offspring rats on PND21 and PND42 in the nano- lead group were significantly lower than those in the control group (7.77 ± 2.16 times vs 11.2 ± 1.61 times, P<0.05; 8.12 ± 1.51 times vs 13.0 ± 2.21 times, P<0.05).

ONCLUSIONn Nano-lead exposure can result in iron homeostasis disorders in the hippocampus and cortex of offspring rats and affect their learning and memory ability.

Animals ; Cerebral Cortex ; drug effects ; metabolism ; Female ; Hippocampus ; drug effects ; metabolism ; Homeostasis ; Iron ; metabolism ; Lead ; toxicity ; Learning ; drug effects ; Maternal Exposure ; adverse effects ; Memory ; drug effects ; Pregnancy ; Rats ; Rats, Sprague-Dawley