Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, PL 31-343 Kraków, Poland.
Pharmacol Rep. 2009 Nov-Dec;61(6):1192-7. doi: 10.1016/s1734-1140(09)70183-5.
The effects of repeated administration of morphine and methadone, followed by a challenge dose of either morphine or methadone were examined ex vivo in rat frontal cortical slices that were prepared 1 h after final drug administration. Morphine challenge dose (5 mg/kg), administered 14 days after the end of repeated morphine pretreatment (10 mg/kg, administered 7 times) decreased both the AMPA/kainate and the NMDA components of field potentials that were evoked in cortical layer II/III by electrical stimulation. This effect did not occur either when a methadone challenge dose (2.5 mg/kg) was administered instead of morphine or after repeated morphine treatment. Moreover, after repeated methadone treatment (2.5 mg/kg, administered 7 times), neither morphine nor methadone challenge affected AMPA/kainate or NMDA components of the field potentials. These data indicate a specific effect of repeated morphine followed by morphine challenge on cortical glutamatergic transmission.
反复给予吗啡和美沙酮，然后给予吗啡或美沙酮挑战剂量，在末次药物给药后 1 小时制备的大鼠额皮质切片中进行了体外研究。吗啡挑战剂量（5mg/kg）在反复吗啡预处理（10mg/kg，7 次给药）结束后 14 天给予，可降低由电刺激在皮质层 II/III 中诱发的场电位的 AMPA/KA 和 NMDA 成分。当给予美沙酮挑战剂量（2.5mg/kg）代替吗啡或在反复给予吗啡后，均未发生这种作用。此外，在反复给予美沙酮治疗（2.5mg/kg，7 次给药）后，吗啡或美沙酮挑战均不影响场电位的 AMPA/KA 或 NMDA 成分。这些数据表明，反复给予吗啡后再给予吗啡挑战对皮质谷氨酸能传递具有特异性作用。
