Effects of early life PM2.5 exposure on prefrontal cortex of offspring male rats / 中国应用生理学杂志

Objective: To investigate the effects of PM2.5 exposure at different stages of early life on the prefrontal cortex of offspring rats. Methods: Twelve pregnant SD rats were randomly divided into four groups: Control group (CG), Maternal pregnancy exposure group (MG), Early postnatal exposure group (EP) and Perinatal period exposure group (PP), 3 rats in each group. The pregnant and offspring rats were exposed to clean air or 8-fold concentrated PM2.5. MG was exposed from gestational day (GD) 1 to GD21. EP was exposed from postnatal day (PND) 1 to PND21, and PP was exposed from GD1 to PND21. After exposure, the prefrontal cortex of 6 offspring rats in each group was analyzed. HE staining was used to observe the pathological damage in the prefrontal cortex. ELISA was employed to detect neuroinflammatory factors, and HPLC/MSC was applied to determine neurotransmitter content. Western blot and colorimetry were applied for detecting astrocyte markers and oxidative stress markers, respectively. Results: Compared with MG and CG, the pathological changes of prefrontal cortex in PP and EP were more obvious. Compared with MG and CG, the neuroinflammatory factors (IL-1, IL-6, TNF-α) in PP and EP were increased significantly (P＜0.01), the level of MT were decreased significantly (P＜0.05), and the level of oxytocin (OT) showed a downward trend; the level of neurotransmitter ACh was also increased significantly (P＜0.01). Compared with MG and CG, the GFAP level of PP and EP showed an upward trend, the level of oxidative stress index SOD in PP and EP was decreased significantly (P＜0.01), and the level of ROS was increased significantly (P＜0.01). Compared with the offspring rats of CG and MG, the CAT level of PP was decreased significantly (P＜0.01, P＜0.05). Compared with the offspring rats of CG, the CAT level of EP was decreased significantly (P＜0.05). There was no significant difference in IL-1, IL-6, TNF-α, MT, OT, ACh, GFAP, SOD, ROS and CAT levels between PP and EP, or MG and CG. Conclusion: PM2.5 exposure in early life has adverse effects on the prefrontal cortex of offspring male rats, and early birth exposure may be more sensitive.

Inflammatory mechanism of hippocampal tissue injury induced by PM in nasal drip in mice / 中国应用生理学杂志

To investigate the inflammatory mechanism of nasal instillation of fine particulate matter (PM)on hippocampal tissue injury in mice. Thirty C57BL/6J mice were randomly divided into 3 groups(n=10):control group, low-dose group, high-dose group. The nasal instillation doses of PM in the low-dose group and the high-dose group were 1.5 mg/kg BW and 7.5 mg/kg BW, respectively, and the control group was given saline with an equal volume. Saline was sprayed once every other time for 12 times. The serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were determined by ELISA method. HE staining and electron microscopy were used to observe the pathological changes and ultrastructure of lung tissue and hippocampus. The inflammatory cytokine levels in hippocampus were detected by antibody chip technique. There was no significant effect of PM nasal instillation on serum TNF-α, IL-1β and IL-6 levels (P＞0.05), and there was no obvious pathological changes in lung tissue structure. In hippocampus, low-dose and high-dose PM exposure could lead to disordered neuronal arrangement in the hippocampal CA3 region, and there were neurological changes around the neuron cells and ultrastructural changes such as edema around small blood vessels. Compared with the control group, the levels of inflammatory cytokines such as CX3CL1, CSF2 and TECK in the low-dose group were increased significantly (P ＜0.05), while sTNFR1 was decreased significantly (P＜0.05); the inflammatory factors CX3CL1, CSF2, and TCA-3 were significantly increased in the high-dose group (P＜0.05), while leptin, MIG, and FASLG were significantly decreased (P＜0.05). Nasal instillation of PM can induce tissue damage in the hippocampus of mice, and its mechanism of action may be the olfactory brain pathway. The increasing of TNF-α and IL-6 and the decreasing of sTNFR1 and FASLG may be involved in inflammatory mechanisms.

Injury of rat blood vessels caused by acute ozone exposure and its mechanism / 中国应用生理学杂志

OBJECTIVE@#To investigate the vascular damage effects and possible mechanism of acute exposure to ozone (O) in male Wistar rats.@*METHODS@#One hundred and twenty male Wistar rats were randomly divided into six groups, 20 in each group. The experimental animals were placed in a gas poisoning cabinet, the control group was exposed to filtered air, and the treatment group was exposed to ozone at concentrations of 0.12 ppm, 0.5 ppm, 1.0 ppm, 2.0 ppm, and 4.0 ppm, respectively, for 4 hours. Arterial blood pressure data were obtained by PC-lab medical physiological signal acquisition system. Blood rheology indicators and blood biochemical indicators were detected by Tianjin Dean Diagnostic Laboratory. Serum endothelin-1 (ET-1), homocysteine (HCY), von Willebrand factor (vWF), 8-hydroxydeoxyguanosine (8-OhdG), interleukin (IL-6) and tumor necrosis factor alpha (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) microplate assay. Oxidative stress indicators superoxide dismutase (SOD) activity and malondialdehyde (MDA) were determined by xanthine oxidase method, thiobarbituric acid (TBA) method, reduced glutathione (GSH) and nitric oxide (NO) were tested by using microplate colorimetry. Paraffin sections were prepared from thoracic aorta tissue, and vascular structure was observed by HE staining.@*RESULTS@#Acute exposure to 0.12 ppm ozone could cause a significant increase in arterial systolic blood pressure (SBP). Exposure to different concentrations of ozone could cause a significant increase in plasma viscosity, and the K value of the ESR equation was significantly increased in the 1.0 ppm ozone exposure group. Both the relative and reduced viscosities were significantly reduced at ozone concentrations of 0.5 ppm and 4.0 ppm, while the red blood cell deformation index was increased significantly at ozone concentrations of 0.12 ppm, 0.5 ppm, 1.0 ppm, and 2.0 ppm. Acute ozone exposure resulted in the decrease of total cholesterol content. The content of high-density lipoprotein cholesterol (HDL-C) was significantly reduced in the 0.12 ppm ozone exposure group. When the ozone concentration was higher than 1.0 ppm, the body may also had an inflammatory reaction (increased TNF-α) and oxidative stress (increased MDA, decreased GSH). Acute exposure to ozone could lead to elevated levels of ET-1 in the blood, with significant differences in the 4.0 ppm concentration group, while HCY levels were decreased firstly and then increased, reaching the highest in the 1.0 ppm concentration group. No obvious pathological changes were observed in the thoracic aorta.@*CONCLUSION@#Acute ozone exposure can affect arterial blood pressure, blood rheology and cholesterol metabolism in rats. The possible mechanism is that ozone exposure leads to inflammatory reaction and oxidative stress reaction, causing vascular endothelial function damage, and vascular endothelial cells increase with ozone exposure concentration.

Endocrine Disruption Activity of 30-day Dietary Exposure to Decabromodiphenyl Ethane in Balb/C Mouse / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This study aimed to evaluate the hepatotoxicity, metabolic disturbance activity and endocrine disrupting activity of mice treated by Decabromodiphenyl ethane (DBDPE).</p><p><b>METHODS</b>In this study, Balb/C mice were treated orally by gavage with various doses of DBDPE. After 30 days of treatment, mice were sacrificed; blood, livers and thyroid glands were obtained, and hepatic microsomes were isolated. Biochemical parameters including 8 clinical chemistry parameters, blood glucose and hormone levels including insulin and thyroid hormone were assayed. The effects of DBDPE on hepatic cytochrome P450 (CYP) levels and activities and uridinediphosphate-glucuronosyltransferase (UDPGT) activities were investigated. Liver and thyroid glands were observed.</p><p><b>RESULTS</b>There were no obvious signs of toxicity and no significant treatment effect on body weight, or liver-to-body weight ratios between treatment groups. The levels of ALT and AST of higher dose treatment groups were markedly increased. Blood glucose levels of treatment groups were higher than those of control group. There was also an induction in TSH, T3, and fT3. UDPGT, PROD, and EROD activities were found to have been increased significantly in the high dose group. Histopathologic liver changes were characterized by hepatocyte hypertrophy and cytoplasmic vacuolization. Our findings suggest that DBDPE can cause a certain degree of mouse liver damage and insufficiency.</p><p><b>CONCLUSION</b>DBDPE has the activity of endocrine disruptors in Bal/C mice, which may induce drug-metabolizing enzymes including CYPs and UDPGT, and interfere with thyroid hormone levels mediated by AhR and CAR signaling pathways. Endocrine disrupting activity of DBDPE could also affect the glucose metabolism homeostasis.</p>

Single wall carbon nanotube induced inflammation in cruor-fibrinolysis system / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study single wall carbon nanotubes (SWCNT) and its role in inducing inflammatory cytokines in the cruor-fibrinolysis system of rat.</p><p><b>METHODS</b>Twenty one Wistar rats were divided into four groups: 1) control; 2) low-dose SWCNT (0.15 mg/kg BW); 3) medium-dose SWCNT (0.75 mg/kg BW); 4) high-dose SWCNT (1.5 mg/kg BW). Intratracheal instillation of SWCNT suspensions was administered to rats once per day for 21 days. In order to assess the exposure effect of SWCNT to the rats, activity of Inflammatory cytokine was measured and markers of cruor-fibrinolysis system were studied via ELSIA. Also, change in clotting time was recorded and histopathology was studied.</p><p><b>RESULTS</b>IL-6 and IL-8 concentrations of rats exposed to SWCNT were significantly higher than those in controls (P<0.05). The activity of inflammatory cytokines and histopathological change indicated that oxidative damage occurred. Change in clotting time in rats exposed to SWCNT decreased compared with controls. Meanwhile, t-PA (tissue-tupe plassminogen activator) and AT-III (antithrombin-III) levels in rats exposed to particulates increased or decreased significantly compared with controls (P<0.05). A similar trend was observed for D-dimer (D2D) levels, indicating that SWCNT can impact the cruor-fibrinolysis system of rat.</p><p><b>CONCLUSION</b>The results from our study suggest that an increased procoagulant activity and reduced fibrinolytic activity in rats exposed to SWCNT can cause pulmonary oxidative stress and inflammation, due to the release of pro-thrombotic and inflammatory cytokines into the blood circulation of rat.</p>