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Effects of Simulated Heat Waves with Strong Sudden Cooling Weather on ApoE Knockout Mice.

Zhang S, Kuang Z, Zhang X - Int J Environ Res Public Health (2015)

Bottom Line: After 55, 59, and 75 h of exposure, the experimental groups were successively removed from the chamber to monitor physiological indicators.NE and ANGII are vasoconstrictors involved in systemic vasoconstriction especially in the superficial areas of the body and conducive to increased blood pressure.The increase in the blood lipid levels of TG, LDL-C, TC, and LDL-C/HDL-C further aggravated CVD.

View Article: PubMed Central - PubMed

Affiliation: Hebei Provincial Meteorological Bureau, 178 Tiyu South Street, Shijiazhuang 050021, China. zhangsy@cma.gov.cn.

ABSTRACT
This study analyzes the mechanism of influence of heat waves with strong sudden cooling on cardiovascular diseases (CVD) in ApoE-/- mice. The process of heat waves with strong sudden cooling was simulated with a TEM1880 meteorological-environment simulation chamber according to the data obtained at 5 a.m. of 19 June 2006 to 11 p.m. of 22 June 2006. Forty-eight ApoE-/- mice were divided into six blocks based on their weight. Two mice from each block were randomly assigned to control, heat wave, temperature drop, and rewarming temperature groups. The experimental groups were transferred into the climate simulator chamber for exposure to the simulated heat wave process with strong sudden temperature drop. After 55, 59, and 75 h of exposure, the experimental groups were successively removed from the chamber to monitor physiological indicators. Blood samples were collected by decollation, and the hearts were harvested in all groups. The levels of heat stress factors (HSP60, SOD, TNF, sICAM-1, HIF-1α), cold stress factors (NE, EPI), vasoconstrictor factors (ANGII, ET-1, NO), and four items of blood lipid (TC, TG, HDL-C, and LDL-C) were measured in each ApoE-/- mouse. Results showed that the heat waves increased the levels of heat stress factors except SOD decreased, and decreased the levels of vasoconstrictor factors and blood lipid factors except TC increased. The strong sudden temperature drop in the heat wave process increased the levels of cold stress factors, vasoconstrictor factors and four blood lipid items (except the level of HDL-C which decreased) and decreased the levels of heat stress factors (except the level of SOD which increased). The analysis showed that heat waves could enhance atherosclerosis of ApoE-/- mice. The strong sudden temperature drop during the heat wave process increased the plasma concentrations of NE and ANGII, which indicates SNS activation, and resulted in increased blood pressure. NE and ANGII are vasoconstrictors involved in systemic vasoconstriction especially in the superficial areas of the body and conducive to increased blood pressure. The increase in the blood lipid levels of TG, LDL-C, TC, and LDL-C/HDL-C further aggravated CVD. This paper explored the influence mechanism of the heat waves with sudden cooling on CVD in ApoE-/- mice.

No MeSH data available.


Related in: MedlinePlus

Variations of ET-1 (a), NO (b), and NO/ET-1 (c) in mice. Compared with the control group, * p < 0.01; Compared with the heat wave group, # p < 0.01; Compared with the temperature drop group, △ p < 0.01.
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ijerph-12-05743-f002: Variations of ET-1 (a), NO (b), and NO/ET-1 (c) in mice. Compared with the control group, * p < 0.01; Compared with the heat wave group, # p < 0.01; Compared with the temperature drop group, △ p < 0.01.

Mentions: Figure 2a–c show the expression levels of ET-1, NO, and NO/ET-1, respectively, in mouse plasma after stimulation. During the heat wave process, the expression level of ET-1 in mouse plasma decreased significantly, with a value of 2.01 ng/L (p < 0.01). After experiencing the temperature drop, the level of ET-1 in the temperature drop group rapidly increased compared with the control group and heat wave groups, which significantly (p < 0.01) increased by 1.82 ng/L and 3.83 ng/L, respectively. As the temperature rewarmed, the expression level of ET-1 in the rewarming temperature group decreased slightly compared with that in the control and temperature drop groups. The change was statistically significant (p < 0.01), but was not significant between the rewarming temperature and heat wave groups (p > 0.05). A strong sudden temperature drop in the heat wave process affected the ET-1 levels of ApoE−/− mice. After heat stimulation, the expression level of NO in the heat wave group was significantly higher than that in the control group (p < 0.01) and the increase was 2.31 μmol/L. In contrast, a strong sudden temperature drop reduced the expression level of NO in the temperature drop group compared with the control and heat wave groups, which decreased by 13.69 μmol/L and 20.04 μmol/L, respectively. Both decreases were statistically significant (p < 0.01).


Effects of Simulated Heat Waves with Strong Sudden Cooling Weather on ApoE Knockout Mice.

Zhang S, Kuang Z, Zhang X - Int J Environ Res Public Health (2015)

Variations of ET-1 (a), NO (b), and NO/ET-1 (c) in mice. Compared with the control group, * p < 0.01; Compared with the heat wave group, # p < 0.01; Compared with the temperature drop group, △ p < 0.01.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4483669&req=5

ijerph-12-05743-f002: Variations of ET-1 (a), NO (b), and NO/ET-1 (c) in mice. Compared with the control group, * p < 0.01; Compared with the heat wave group, # p < 0.01; Compared with the temperature drop group, △ p < 0.01.
Mentions: Figure 2a–c show the expression levels of ET-1, NO, and NO/ET-1, respectively, in mouse plasma after stimulation. During the heat wave process, the expression level of ET-1 in mouse plasma decreased significantly, with a value of 2.01 ng/L (p < 0.01). After experiencing the temperature drop, the level of ET-1 in the temperature drop group rapidly increased compared with the control group and heat wave groups, which significantly (p < 0.01) increased by 1.82 ng/L and 3.83 ng/L, respectively. As the temperature rewarmed, the expression level of ET-1 in the rewarming temperature group decreased slightly compared with that in the control and temperature drop groups. The change was statistically significant (p < 0.01), but was not significant between the rewarming temperature and heat wave groups (p > 0.05). A strong sudden temperature drop in the heat wave process affected the ET-1 levels of ApoE−/− mice. After heat stimulation, the expression level of NO in the heat wave group was significantly higher than that in the control group (p < 0.01) and the increase was 2.31 μmol/L. In contrast, a strong sudden temperature drop reduced the expression level of NO in the temperature drop group compared with the control and heat wave groups, which decreased by 13.69 μmol/L and 20.04 μmol/L, respectively. Both decreases were statistically significant (p < 0.01).

Bottom Line: After 55, 59, and 75 h of exposure, the experimental groups were successively removed from the chamber to monitor physiological indicators.NE and ANGII are vasoconstrictors involved in systemic vasoconstriction especially in the superficial areas of the body and conducive to increased blood pressure.The increase in the blood lipid levels of TG, LDL-C, TC, and LDL-C/HDL-C further aggravated CVD.

View Article: PubMed Central - PubMed

Affiliation: Hebei Provincial Meteorological Bureau, 178 Tiyu South Street, Shijiazhuang 050021, China. zhangsy@cma.gov.cn.

ABSTRACT
This study analyzes the mechanism of influence of heat waves with strong sudden cooling on cardiovascular diseases (CVD) in ApoE-/- mice. The process of heat waves with strong sudden cooling was simulated with a TEM1880 meteorological-environment simulation chamber according to the data obtained at 5 a.m. of 19 June 2006 to 11 p.m. of 22 June 2006. Forty-eight ApoE-/- mice were divided into six blocks based on their weight. Two mice from each block were randomly assigned to control, heat wave, temperature drop, and rewarming temperature groups. The experimental groups were transferred into the climate simulator chamber for exposure to the simulated heat wave process with strong sudden temperature drop. After 55, 59, and 75 h of exposure, the experimental groups were successively removed from the chamber to monitor physiological indicators. Blood samples were collected by decollation, and the hearts were harvested in all groups. The levels of heat stress factors (HSP60, SOD, TNF, sICAM-1, HIF-1α), cold stress factors (NE, EPI), vasoconstrictor factors (ANGII, ET-1, NO), and four items of blood lipid (TC, TG, HDL-C, and LDL-C) were measured in each ApoE-/- mouse. Results showed that the heat waves increased the levels of heat stress factors except SOD decreased, and decreased the levels of vasoconstrictor factors and blood lipid factors except TC increased. The strong sudden temperature drop in the heat wave process increased the levels of cold stress factors, vasoconstrictor factors and four blood lipid items (except the level of HDL-C which decreased) and decreased the levels of heat stress factors (except the level of SOD which increased). The analysis showed that heat waves could enhance atherosclerosis of ApoE-/- mice. The strong sudden temperature drop during the heat wave process increased the plasma concentrations of NE and ANGII, which indicates SNS activation, and resulted in increased blood pressure. NE and ANGII are vasoconstrictors involved in systemic vasoconstriction especially in the superficial areas of the body and conducive to increased blood pressure. The increase in the blood lipid levels of TG, LDL-C, TC, and LDL-C/HDL-C further aggravated CVD. This paper explored the influence mechanism of the heat waves with sudden cooling on CVD in ApoE-/- mice.

No MeSH data available.


Related in: MedlinePlus