1. Rabbits received naloxone HCl intracerebroventricularlyor naloxone methiodide IV, a quaternary compound that does notcross the blood–brain barrier, 5 min before FENT treatment(5 or 50 g/kg, IV).
使用 FENT 治疗（5或50 g/kg ，静脉注射）前5min ，向家兔脑室内注射盐酸纳洛酮或静脉注射甲硫丁氨酸纳洛酮（一种四元化合物，不能透过血脑屏障）。