| Objective:To observe the influence of chronic cold stress on expression of endothelium-1(ET-1) and calcitonin gene related peptide (CGRP) in plasma and brain tissue ofrenovascular hypertensive rats (RHR), and to investigate the relationship betweenET-1, CGRP and hypertensive stroke.Methods:RHR modle were made with the operation of2-kidney,1-clip (2k1c). After8weeks of the operation,10rats from the RHR modle group and10rats from thecontrol group(normal systolic blood pressure), were selected respectively,then therats were sacrificed, plasma and brain tissue were saved. Before the chronic coldstress, each group (RHR modle group and control group) was further subdivided intotwo groups: chronic cold stress group and non-chronic cold stress group. The rats ofchronic cold stress group were exposed to cold4℃for4h a day, while in thenon-chronic cold stress group, the rats were exposed to cold23℃for4h a day.After8th weeks of chronic cold stress, all subgroups rats were sacrificed, and plasma wassaved to measure the expression of ET-1and CGRP by Enzyme-linkedimmunosorbent assay (ELISA) and brain tissue was collected to measure theexpression of ET-1and CGRP by immunohistochemistry. SBP was measured beforethe operation and every two weeks after the operation until the end of the experiment.Results:(1) Result of SBP：Compared with the control group, the SBP level of RHR modle group was significantly higher after2weeks of operation (P<0.05). Stablehypertension was formed after6weeks of operation in RHR modle group. After4weeks of chronic cold stress, the SBP expression of control chronic cold stress groupwas significantly higher than that of the control non-chronic cold stressgroup(P<0.05). The SBP level of RHR chronic cold stress group was significantlyhigher than that of the RHR non-chronic cold stress group(P<0.05) after6weeks ofchronic cold stress.(2)The expression of ET-1and CGRP in plasma and brain tissue After8weeks ofoperation, compared with the control group the expression of ET-1and CGRP in RHRmodle group were both significantly higher than that in plasma and brain tissue,respectively (P<0.05). After8weeks of chronic cold stress, the ET-1and CGRP ofcontrol chronic cold stress group was significantly higher than that of the controlnon-chronic cold stress group in plasma and brain tissue (P<0.05).Compared with theRHR non-chronic cold stress group, the ET-1of RHR chronic cold stress group wassignificantly higher in in plasma and brain tissue while the CGRP was significantlylower in plasma and brain tissue (P<0.05).Conclusion:1、The expression of ET-1and CGRP significantly were increased in plasma andbrain tissue of RHR.2、Chronic cold stress can futher increase the expression of ET-1in plasma andbrain tissue of RHR,but reduce the expression of CGRP in plasma and brain tissue ofRHR. |
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