Research On Effect Of Cold Air From Northwest China On Hypertension Diseases And Its Mechanism

Gansu province is located in the northern China? where climate type complex, the changeable weather, large temperature difference.95%of cold air, which affect china, go through Gansu. Research shows that cold air can increase the severity of hypertension disease, increase apoplexy and myocardial infarction which are related with hypertension. The morbidity of our hypertension is higher than some other countries. So the bad weather condition is harmful to locals. But the biological mechanisms of hypertension have not been understood. The results of cold air can’t satisfy the need of time scale, when we want to know the biological mechanisms of hypertension. To solve this problem, cold air models are built with downscaling method and simulated in the environmental test chamber. Toxicology test have been carried out to prove the effect of cold air to blood pressure、heart rate、weight、 adrenalin、angiotensinⅡand blood viscosity, in order to know the relation and pathogenesis between cold air and morbidity and mortality of hypertension. To be ready for forecast hypertension, offer some reference. Main conclusion:(1):Cold air models built with statistical downscaling method can simulate temperature and pressure of cold air well. Offer real-time value of temperature and pressure for toxicology test. This is beneficial to analyse the variation of rats’ indication. Be ready for the future research;(2):Stimulated by cold air, the SBP of experimental group is higher than control group, and the SBP of low-temperature group are maximum. It shows that the more lower of temperature, the more susceptible of rats. Be stimulated by same cold air, healthy rats are more susceptible than SHR. So cold stimulus can increase the rate of hypertension of healthy rats, increase the risk of SHR.(3):The HR of low-temperature group arrives at the highest value, and hypertension-group rises more apparently. The results show that HR of all groups are not statistically significant (P>0.05), it means the change of HR have not been influence by cold air;(4):Compared with the control-group, cold makes the EPI and AngⅡ increase, The EPI of return-temperature group and the Ang Ⅱ of low-temperature group arrive at the highest value, the EPI of healthy-group and the Ang Ⅱof hypertension-group rise more apparently. But EPI of all groups are not statistically significant (P>0.05). It means that the change of EPI is not related with cold air. Ang Ⅱis statistically significant between Low-temperature group of Wistar and control-group, P<0.01. Cold makes Ang II increase, the more lower of temperature, the more susceptible of rats, Wistar is more susceptible. Rising of Ang II activate the RAS system, which lead to the rise of SBP. Because the Ang Ⅱ has strong vascular contractility capacity, interacting with receptor, AT-1, Ang Ⅱrole in the vascular smooth muscle, stimulates the whole body arteriole contraction, leads to high blood pressure. Therefore, be stimulated by cold air, blood pressure increase by activating the RAS system, eventually leading to the rise of blood pressure;(5):Compared with the control-group, cold makes the WBV increase, The WBV of low-temperature group and return-temperature group of SHR arrive at the highest, and the low-temperature group of Wistar is more susceptible. The difference between low-temperature of Wistar、back-temperature group of SHR and control-group are statistically significant while other difference has no significance. Blood viscosity is also a factor of peripheral resistance, so cold air make whole blood viscosity rise.Spontaneously hypertensive rats(SHR) and human spontaneously hypertension have much in common, The common characteristic is genetic factors predominant, Early in the hypertension has no obvious organic change, the course are similar, The SBP and vascular resistance are sensitive to cold stimulus, suitable for hypertension research. It is feasible to gather pathogenesis of people from rats. So we can infer that cold stimulus makes SBP and Ang II of patients with hypertension increase, which lead to increase the rate of hypertension. Just because the rate of hypertension increase, condition of hyperpietic will be worse, and healthy people looks increasingly likely to get high blood pressure.