一氧化氮合酶抑制剂对7d尾部悬吊大鼠心血管脱锻炼的对抗效应  

Effects of NO Synthases Inhibitor on Cardiovascular Deconditioning in Rats after 7 d Tail-suspension.

作　　者：汪德生[1] 梁文彬[1] 袁明[1] 刘朝霞[1] 张淑静[1] 李志利[1] 

机构地区：[1]航天医学工程研究所,北京100094

出　　处：《航天医学与医学工程》2003年第6期405-409,共5页Space Medicine & Medical Engineering

基　　金：中国载人航天工程基金资助

摘　　要：目的揭示模拟微重力大鼠心血管脱锻炼 (CVD)病理生理学变化 ;探索一氧化氮合酶抑制剂对抗模拟微重力大鼠CVD的效应。方法 - 30° 7d尾部悬吊 (TS 7d)模拟微重力生理效应。Wistar大鼠被随机分成 3组 :自由活动对照组 (CON)、7d尾部悬吊组 (TS 7d)和 7d尾部悬吊后用药组 (TS 7d +L NAME )。头向上倾斜 90°( + 90°HUT) 1 2 0min模拟立位应激时的生理效应 (simulatedorthostatism ,SO)。 1 0 - 6 MN 硝基 L 精氨酸甲酯 (N nitro L argininemethylester ,L NAME)经舌下静脉注射给药。PowerLab生理记录系统检测SO 1 2 0min颈动脉压和肢Ⅱ导心电 ,分析平均动脉压 (MAP)和心率(HR)。结果CON大鼠仅在SO 1 2 0min时出现一次低血压、心动过缓情节 ,TS 7d大鼠出现 7次低血压、心动过缓情节 ,TS 7d +L NAME大鼠仅MAP在SO 1 0min与CON大鼠比显著升高 ,其余参数在平卧位或SO期间与CON大鼠变化无差异。结论TS 7d大鼠出现的CVD与NO产生量增加有关 ,1 0 - 6 ML NAME能较好对抗CVD效应 ,可能与L NAME同NOS结合增加外周血管阻力和中枢交感输出增加有关 ,L NAME对血管周神经和肺循环动脉系统的作用在其中的贡献有待于进一步研究。Objective To disclose the changes in pathophysiology of cardiovascular deconditioning(CVD) induced by tail-suspension(TS) and to explore the effects of NOS inhibitor on CVD in TS rats. Method -30° tail suspended rats were used as the model to simulate the physiological effects of microgravity. Wistar rats were randomly arranged into: control group(CON), 7 d TS group(TS 7 d) and TS 7 d+NOS inhibitor group(TS 7 d+ L-NAME). Then, all the rats were subjected to +90° head-up tilt to simulate the physiological effects of orthostatic stress(SO) after 7 d tail-suspension, only that the TS 7d+ L-NAME rats were injected with 10 -6 M L-NAME (N-nitro-L-arginine methylester) through hypoglossal vein before tilting after 7 d TS. Carotid pressure and limb II ECG were measured with a PowerLab physiological system during 120 min tilt, and mean arterial pressure(MAP) and heart rate(HR) were analysized. Result Only one transient episode of hypotension-bradycardia appeared during the tilt in CON rats, but seven episodes occurred in TS 7 d rats, while the TS 7 d+L-NAME rats has only a significant increase in MAP at 10 min. No differences were found between the other parameters in recumbent position and those during the tilt. Conclusion The CVD in the rats induced by TS is relative to an increase of NO production. 10 -6 M L-NAME had an alleviating effects on the CVD, which might be due to the increase of peripheral resistance of blood vessels and the central sympathetic drive by the combination of L-NAME with NOS. The contribution of the perivascular nerves and pulmonary arteries to this effect remains to be further studied.

关 键 词：失重模拟 心血管脱锻炼 N-硝基-L-精氨酸甲酯 对抗措施 

分 类 号：R852.22[医药卫生—航空、航天与航海医学]