[Effects and mechanisms of negative air ions on blood pressure, oxidative stress and inflammation levels in SHR rats].

OBJECTIVE: To investigate the effects and possible mechanisms of negative air ions(NAIs) on blood pressure, oxidative stress, and inflammatory status in spontaneous hypertension rats(SHR). METHODS: A total of 60 SHR(half male and half female) were randomly divided into one-month and three-month groups, 30 rats per groups, based on the duration of the intervention. Each group was further randomized into three groups based on the daily intervention time: SHR control group, 2 h NAIs-SHR group, and 6 h NAIs-SHR group, 10 rats per groups. In addition, 20 Wistar Kyoto(WKY)(half male and half female), were randomized into one-month WKY group and three-month WKY group, 10 rats per groups, based on the intervention time. The 2 h NAIs-SHR group and 6 h NAIs-SHR group were exposed to an environment with NAIs concentrations of 4.5×10~4-5×10~4 cm~3 per day for 2 h and 6 h. The WKY group and SHR group were exposed to normal air on a daily basis. Blood pressure of rats in each group was measured every three days, while weight was measured once a week. After sacrificing the rats in the first month and the third month of rearing, wet weight of the organs was weighed. The enzyme linked immunosorbent assay(ELISA) was used to detect 8-hydroxylated deoxyguanosine(8-OHdG), interleukin-6(IL-6), interleukin-8(IL-8), tumor necrosis factor-α(TNF-α), nitric oxide(NO) and endothelin-1(ET-1) levels. Reactive oxygen species(ROS) detection kit was used to detect ROS level. Malondialdehyde(MDA) and superoxide dismutase(SOD), glutathione(GSH) and glutathione disulfide(GSSG) were measured by colorimetric analysis. HE staining was conducted to observe the histopathological morphological changes of the thoracic aorta in each group, and Western blot was conducted to detect the thoracic aortap38 mitogen-activated protein kinase(p38 MAPK), extracellular signal-regulated kinases(ERK), c-Jun n-terminal kinase(JNK), c-fos proteins, c-jun proteins and their phosphorylated proteins level. RESULTS: The weight of WKY male mice in the same week age group was higher than that of SHR control group, and there was no significant difference in the weight between the other groups. The coefficient of heart in SHR control group(4.66±0.48) was higher than that in WKY group(3.73±0.15)(P<0.05), while there were no significant differences in the coefficients of brain, kidney, liver and spleen among the groups. Blood pressure in WKY group at the same age was lower than that in SHR group, and blood pressure in SHR control group at 2-5 and 8-11 weeks was higher than that in 2 h NAIs-SHR and 6 h NAIs-SHR groups(P<0.05). HE staining showed that the internal, middle and external membranes of thoracic aorta in 2 h NAIs-SHR group and 6 h NAIs-SHR group were improved to varying degrees compared with those in SHR control group, including disordered internal membrane structure, thickened middle membrane and broken external membrane. In terms of oxidative stress levels, compared with the SHR control group, the ROS(0.66%±0.17%, 0.49%±0.32%) and 8-OHdG((48.29±8.00) ng/mL, (33.13±14.67)ng/mL) levels were lower in the 6 h NAIs-SHR group(P<0.05), while the GSH/GSSG ratio was higher in the one-month 6 h NAIs-SHR group(10.08±4.93). Compared with the 2 h NAIs-SHR group, the ROS level(0.99%±0.19%) was lower in the 6 h NAIs-SHR group(P<0.05). In terms of inflammatory factor levels, compared with the SHR control group, the IL-8 levels((160.44±56.54) ng/L, (145.77±38.39) ng/L) were lower in the 6 h NAIs-SHR group(P<0.05), while the ET-1 level((249.55±16.98) ng/L) was higher in the one-month WKY group. There was no significant difference in NO levels among the groups. The relative expression of p-p38 protein in the thoracic aorta of rats in the one-month SHR control group was lower than that in the WKY group(P<0.05). The relative expression of p-p38 and p-c-fos proteins in the thoracic aorta of rats at three-months was higher in the SHR control group than in the 2 h NAIs-SHR and 6 h NAIs-SHR groups(P<0.05). CONCLUSION: The intervention of NAIs at a concentration of 4.5×10~4-5×10~4/cm~3 may regulate the partial oxidation and inflammatory state of SHR rats through the ROS/MAPK/AP1 signaling pathway, thereby reducing their blood pressure level.

Effect of beta-cypermethrin on the reproductive capacity of female mice in advanced age.

The aim of the present study was to investigate whether exposure to pesticides beta-cypermethrin (ß-CYP) harms the reproductive capacity of advanced-age female mice. The results evidenced that peri-implantation ß-CYP exposure significantly reduced the number of fetuses per advanced-age female in the first litter, and the number and weight of implantation sites. The levels of decidualization markers were significantly reduced in ß-CYP-administered advanced-age mice. Lower expression of Pcna, Cdk6, Foxo1, Ki67, and p62 protein and mRNA was found in the decidua of ß-CYP-treated advanced-age mice. The levels of Bax, cleaved caspase-3, Lc3a/b, Atg, mTOR, and p-mTOR protein, and the ratio of p-mTOR/mTOR protein expression were clearly downregulated by peri-implantation ß-CYP exposure. These results indicated that peri-implantation ß-CYP exposure may elevate the decline in reproductive capacity of early pregnant mice in advanced age.

[Effects of intragastric administration of formaldehyde on superoxide dismutase activities and malondialdehyde contents in liver of mice].

OBJECTIVE: To study the effects of intragastric administration of formaldehyde on lipid peroxidation in mice. METHODS: Thirty ICR mice were randomly divided into 3 groups: one control group and two experimental groups. The mice were given formaldehyde (the dose is 0, 5 and 20 mg/kg body weight respectively) through intragastric administration once a day for 5 days , and then they were killed. The activities of SOD and the contents of MDA in liver were measured. RESULTS: The activities of SOD in the 20 mg/kg body weight group were significantly lower than the control group (P < 0.05), and the contents of MDA in the 20 mg/kg body weight group were significantly higher than the control group (P < 0.05), and the liver organ coefficient in the 20 mg/kg body weight group is higher than the control group (P < 0.05). CONCLUSION: A certain dose of formaldehyde can destroy the balance of lipid peroxidation in mice, the ability of antioxidation is reduced obviously, and the liver become compensatory hypertrophy.