间断性—Gx对抗尾部悬吊大鼠脑动态反应的效果研究

目的：探讨不同G值的间断性－Gx暴露对抗模拟失重下大鼠脑基底动脉管反应性改变的效果。方法：用大鼠在1．5G或2．6G的离心机上离心模拟不同G值间断性－Gx暴露，分别给予大鼠（尾悬吊3wk)1h/d－Gx作用，测定大鼠离体基底动脉血管环对KCl的收缩反应性。结果：悬吊组大鼠基底动脉血管环对KCl的最大反应较对粗显著升高（P＜0．05）；间断性－Gx重力暴露组大鼠基底动脉血管环对KCl的最大反应较悬吊组显著减弱（P＜0．05），与对照组无显著判别。结论：间断性－Gx暴露可抗模拟失重对大鼠脑动脉血管反应性的影响，而这种对抗作用不随重力G值的改变而改变。

Counteraction Effect of Intermittent -Gx on Changes of Responsiveness of Basilar Artery in Tail-suspended Rats.

Objective To investigate counteracting effects of intermittent -Gx exposure on changes of responsiveness of basilar artery in tail suspended rats. Method Rats tail suspended for 3 wk were daily subjected to 1 h 1.5 G or 2.6 G centrifugation, simulating -Gx exposure of various G values. Responses of perfused isolated basilar arterial rings to KCl was examined. Result Maximal isometric contractile response to KCl were significantly enhanced in arterial rings isolated from 3 wk tail suspended rats as compared with that from simultaneous control rats (P<0.05). However, maximal isometric contractile responses to KCl of arterial rings isolated from 3 wk tail suspended plus daily -Gx exposure rats were no difference as compared with that from simultaneous control rats, and were significantly decreased (P<0.05) as compared with that from 3 wk tail suspended rats. Conclusion Daily intermittent -Gx exposure as a countermeasure to prevent the effects of simulated weightless on changes in responsiveness of basilar artery from tail suspended rats was valid.