| 摘要: |
| 目的 探讨固定时间热暴露对大鼠胸主动脉血管收缩特性的影响及机制。方法 选用雄性Wistar大鼠，随机分为对照组、随意时间热暴露组和固定时间热暴露组，环境温度24℃，热暴露温度为36℃，每天热暴露6 h。经7 d热暴露后,采用体温遥感技术监测大鼠体核温度变化；器官浴槽法测定大鼠胸主动脉对去甲肾上腺素(NA)的反应性；RT-PCR检测动脉血管内皮型一氧化氮合酶(eNOS) mRNA的表达水平及用试剂盒测定血浆中一氧化氮等离子体(NOx) NO2-和NO3-的含量变化。结果 热暴露对大鼠的体核温度变化影响不大(P>0.05)；与对照组相比,固定时间热暴露组大鼠胸主动脉血管对NA的反应性降低(P<0.01);与对照组和随意时间热暴露组相比，固定时间热暴露组eNOS mRNA相对表达水平及血浆中NOx的含量增加(P<0.05)。 结论 固定时间热暴露可改变大鼠胸主动脉血管的反应性,内皮细胞源性的NOS通路可能参与并诱导了血管舒张作用。 |
| 关键词: 热 体温 血管收缩 胸主动脉 |
| DOI：10.3724/SP.J.1008.2013.00291 |
| 投稿时间：2012-12-04修订日期：2013-02-26 |
| 基金项目:国家自然科学基金(81060230),宁夏医科大学校级重点孵育科研项目(XZ2012005). |
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| Effects of heat exposure during fixed time on thoracic aorta contractility in rats |
| LI Guang-hua1*,ZHAO Nan1,YANG Min1,ZHAO Zhi-fang1,LUO Yan1,Osamu Shido2 |
(1. Department of Physiology, School of Basic Medical Science, Ningxia Medical University, Yinchuan 750004, Ningxia, China
2. Department of Environmental Physiology, School of Medicine Shimane University, Izumo 693-8501, Japan
*Corresponding author.) |
| Abstract: |
| Objective To investigate the effect of heat exposure during fixed time on the thoracic aorta contractile properties of rats and the related mechanism. Methods Male Wistar rats were randomly divided into control group, random-time heat exposure group and fixed-time heat exposure group (ambient temperature to 24℃；the two heat exposure groups were exposed to heat \[36℃\] 6 h daily). After 7 days of heat exposure, the body core temperature of rats was measured by telemetry technology. The response of isolated thoracic aorta to noradrenaline (NA) was determined by organ bath system. Expression of aorta eNOS mRNA and plasma NOx (NO2-and NO3-) content were also examined. Results Heat exposure showed no significant effects on body core temperature of rats (P>0.05). Compared with control group, the fixed-time heat exposure group had significantly lowered thoracic aortic vascular reactivity to NA (P<0.01). Compared with control group and random-time heat exposed group, the fixed-time heat exposure group had significantly increased eNOS mRNA expression and plasma NOx content (P<0.05).Conclusion Fixed-time exposure to heat can change the reactivity of the thoracic aorta in rats, and vascular endothelial cell-derived NOS pathway may be involved in the vasodilatory effects. |
| Key words: heat body temperature vasoconstriction thoracic aorta |
