Shi Hong-mei, He Li-hua, Zhang Ying, Ye Kang-ping, Chang Dou, Liu Tong-tong, Wang Sheng
Department of Occupational and Environmental Health, School of Public Health, Peking University, Beijing 100083, China.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2007 Apr;25(4):197-9.
To study the changes of nitric oxide(NO) and nitric-oxide synthase(NOS) in the development of cold-induced hypertension (CIH).
Sixty male Sprague-Dawley adult rats were used. Thirty were exposed to cold (4 +/- 1) degrees C as cold-treated group while the other 30 were at (25 +/- 1) degrees C as controls, 4 hours a day for 6 weeks for both groups. Systolic blood pressure (SBP) and heart rate were measured twice every week. Each group was further subdivided into three groups, 10 rats each. A subgroup of the cold-treated and control rats were sacrificed at 2, 4 and 6 week. Plasma was saved to measure superoxide dismutase (SOD) and malondiadehycle (MDA), while heart was homogenated to measure NO, NOS.
1 SBP increased during 6 weeks of exposure to cold. From the second week, SBP of cold-treated group [(94.16 +/- 3.81) mm Hg] was significantly greater than that of control group [(88.77 +/- 4.45 mm Hg), P<0.01]. The highest SBP level was achieved at the sixth week [(116.78 +/- 3.79)mm Hg, P<0.01]. 2 Compared to the control group, SOD in cold-treated group decreased significantly from the second week, and maintained throughout the time of exposure to cold (P<0.05). MDA levels did not differ significantly between cold-treated and control groups though it increased mildly during 6 weeks of cold exposure (P>0.05). Heart NOS in cold-treated group decreased significantly from the fourth week to the sixth week. And a mild decrease was observed in heart NO of cold-treated group during 6 weeks of exposure (P>0.05).
Cold-induced hypertension is induced in rats after repeated exposure to cold. The levels of NOS, NO decrease accordingly to the rise of blood pressure. This indicates that the dysfunction of NO and NOS is involved in the development of CIH.
研究冷诱导高血压（CIH）发生发展过程中一氧化氮（NO）和一氧化氮合酶（NOS）的变化。
选用60只成年雄性Sprague-Dawley大鼠。30只置于（4±1）℃低温环境作为冷处理组，另外30只置于（25±1）℃作为对照组，两组均每天暴露4小时，持续6周。每周测量两次收缩压（SBP）和心率。每组再进一步分为三组，每组10只。冷处理组和对照组的一个亚组分别在第2、4和6周处死。保存血浆用于检测超氧化物歧化酶（SOD）和丙二醛（MDA），同时取心脏匀浆检测NO、NOS。
大鼠反复暴露于寒冷环境可诱发冷诱导高血压。NOS、NO水平随血压升高而相应降低。这表明NO和NOS功能异常参与了CIH的发生发展。
