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目的为探讨失重对动脉血管系统的影响，观察模拟失重大鼠肠系膜小动脉血管反应性的变化。方法采用恒流灌流法观察１４天尾部悬吊模拟失重大鼠肠系膜血管床反应性的变化，并与对照大鼠比较。结果在基础灌流条件下，悬吊大鼠肠系膜血管床的流量－阻力关系与对照大鼠相比无明显区别；而在恒定流量灌流条件下，ＫＣｌ或者苯肾上腺素（ＰＥ）引起的悬吊大鼠肠系膜血管床升压反应幅度却较对照组显著降低。结论１４天模拟失重已可引起大鼠肠系膜阻力性小动脉血管收缩反应性降低。本研究提示：阻力性动脉血管反应性下降可能是造成飞行后立位耐力不良的重要机理之一。
Objective To investigate the effect of weightlessness on arterial vasculature and to observe the changes of vasoreactivity of mesenteric arterioles in simulated weightless rats. Methods The changes of mesenteric vascular bed reactivity in simulated weightless rats after 14-day tail suspension were observed by constant flow perfusion method and compared with control rats. Results Under basal perfusion, the flow-resistance relationship of mesenteric vascular bed in rats was not significantly different from that in control rats. However, under constant perfusion, KCl or phenylephrine (PE) Rat mesenteric vascular bed pressure response rate was significantly lower than the control group. Conclusion Simulated weightlessness on day 14 has caused a decrease in vasoconstrictor response of rat mesenteric resistance arterioles. This study suggests that decreased resistance to arterial vasoconstriction may be one of the important mechanisms leading to poor standing endurance after flight.