Objective:To study the effects of naloxone on the tail pain threshold and the content of enkephalin and dynophin in brain tissue in rats after alternating action of positive acceleration(+Gz)and negative acceleration(-Gz).

• 目的 :施加正、负加速度交替作用后 ,研究纳络酮对大鼠脑组织脑啡肽、强啡肽的含量及尾部痛阈的影响。