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

International Journal of Environmental Research and Public Health

Shuyu Zhang²  Zhengzhong Kuang¹  Xiakun Zhang³ 

[1] School of Applied Meteorology, Nanjing University of Information Sciences and Technology, 219 Ningliu Road, Nanjing 210044, China; E-Mail:;Hebei Provincial Meteorological Bureau, 178 Tiyu South Street, Shijiazhuang 050021, China; E-Mail:;National Meteorological Centre, 46 Zhongguancun South Street, Beijing 100081, China

关键词: heat wave;    strong cooling;    ApoE−/− mice;    heat stress factor;    cold stress factor;    atherosclerosis;    hypertensive;    mechanism;   

DOI  :  10.3390/ijerph120605743

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.