微电泳OMF和U-50488对大鼠孤束核呼吸相关单位电活动的影响

本工作用微电泳给予μ受体激动剂羟甲芬太尼(OMF)和κ受体激动剂U-50488,主要观察它们各自对大鼠孤束核呼吸相关单位自发放电的影响。 在44个呼吸相关单位中,微电泳给予OMF呈现压抑效应的21个,兴奋效应的7个,双相效应的5个,其余11个单位未见明显改变。在7个OMF产生压抑效应的单位中,有6个单位的压抑效应能被纳洛酮对抗。在3个OMF引起兴奋效应的单位中,有2个单位的兴奋效应能被纳洛酮对抗。 在45个呼吸相关单位中,微电泳U-50488呈压抑效应的15个,兴奋效应的5个,双相效应的3个,其余22个单位自发放电无明显改变。在9个U-50488产生压抑效应的单位中,有7个单位的压抑效应能被纳洛酮对抗。在2个U-50488产生兴奋效应的单位中,1个单位的兴奋效应能被纳洛酮对。在6个OMF产生压抑效应的单位中,4个单位能被U-50488对抗。结果提示OMF和U-50488产生的压抑、兴奋效应可能是由阿片受体介导的,并且可能是由不同亚型受体介导的。

EFFECTS OF MICROIONTOPHORETICALLY APPLIED OMF AND U-50488 ON SPONTANEOUS DISCHARGES OF RESPIRATION RELATED UNITS IN THE REGION OF NUCLEUS OF SOLITARY TRACT OF RAT

It was observed that ohmefentanyl (OMF) and U-50488, when applied mi-croiontophoretically, affected the spontaneous discharges of respiration related units(RRUs) in the nucleus of solitary tract of rat. Of the 44 RRUs recorded, OMFproduced depressive effect in 21, excitatory in 7, biphasic effect in 5 while 11 unitswere not affected. Naloxone administered iontophoretically blocked both thedepressive (6 out of 7) and the excitatory units (2 out of 3). Of the 45 RRUs re-corded, U-50488 produced depressive effect in 15, excitatory in 5, biphasic effectin 3, while 22 units were not affected. Naloxone blocked both the U-50488 de-Pression (7 out of 9) and excitation (1 out of 2) effect. U-50488 antagonized OMF-induced depression in 4 out of 6 units. The results suggest that depression andexcitation produed by OMF and U-50488 may be mediated by different subtypesof opiate receptor.