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 (P0.05). 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 (P0.05) 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.