热浪对小鼠体温的影响及四氢生物蝶呤的保护作用

通过给予小鼠热浪刺激,检测热浪过程前后健康小鼠与ApoE小鼠血浆ET-1、NO及体温的变化。探讨热浪对小鼠体温的影响及BH4在热浪过程中对小鼠的保护机理。利用气象环境模拟箱模拟一次南京市2001年7月的热浪过程,将雄性健康、ApoE小鼠各18只分为对照组,热浪组,热浪BH4组,并将2实验组放入气候箱,每日测量小鼠体重、肛温,并于模拟结束后,检测血管ET-1和NO的含量。结果是热浪刺激使得小鼠体温升高(P<0.01),NO水平上升(P<0.01);ApoE小鼠的体温普遍略高于健康小鼠,NO水平更低(P<0.01),体温上升更加明显(P<0.01)。BH4组小鼠体温变化较对照组没有统计学意义(P>0.05),而血浆NO水平高于未给予BH4的热浪组小鼠。说明热浪刺激使得小鼠NO/ET-1平衡偏向于血管扩张因素,体温上升。ApoE小鼠更易受到热浪的影响,是高温热浪易致冠心病人中暑的可能机理之一。BH4可增加机体散热效率,保护小鼠不易受到热浪影响,对ApoE小鼠的作用尤为显著。

Effects of heat wave on body temperature in mice and the protection of BH4

Abstract: Objective To explore the effects of heat wave on mice and the role of BH4 by comparing the variations of ET-1, NO and body temperature between C57BL/6/J mice and ApoE mice after an artificial heat wave. Methods A heat wave occurred in July 2001 was simulated by climate simulator. 18 male ApoE mice and 18 male healthy mice were divided into the control, heat wave, BH4 group respectively. The groups of heat wave and BH4 were exposed to the simulated heat wave, while the body weight and rectal temperature were measured every day. The content of ET-1 and NO were detected after simulation. Results The NO level and the body temperature were rising obviously(p<0.01) during the heat wave. ApoE mice had a higher body temperature which rose significantly(p<0.01) during the simulation and lower NO level(p<0.01). There was no obvious difference of body temperature between BH4 group and control group(p>0.05), but a higher NO level was detected in BH4 group. Conclusion The vascellums of mice tended to expand during heat which led to high body temperature. ApoE mice were more vulnerable when suffering the heat wave, which might be one of the reasons why coronary artery disease patients were more vulnerable to high temperature. BH4 may protect mice from high environmental temperature by improving the efficiency of dissipating heat, especially for ApoE mice.