Pumford K M, Leng G, Russell J A
Department of Physiology, University Medical School, Edinburgh, UK.
Exp Brain Res. 1993;94(2):247-51. doi: 10.1007/BF00230292.
We investigated the effects of intracerebroventricular (i.c.v.) pertussis toxin upon the sensitivity of supraoptic oxytocin neurones to intravenous morphine (1-5000 micrograms/kg) in urethane-anaesthetized rats. The maximal inhibitory capacity of morphine was diminished by prior administration of pertussis toxin. Some cells were tested with both morphine and with the kappa-opioid agonist U50,488 (1-5000 micrograms/kg): U50,488-induced inhibition of firing rate was apparently unimpaired by pertussis toxin pre-treatment. The opioid inhibition of firing rate seen in the absence of and after pertussis toxin pre-treatment was naloxone-reversible. Thus a pertussis toxin-sensitive G protein may mediate the inhibitory action of morphine upon supraoptic putative oxytocin neurones or inputs to them.
我们研究了在乌拉坦麻醉的大鼠中，脑室内注射百日咳毒素对视上核催产素神经元对静脉注射吗啡（1 - 5000微克/千克）敏感性的影响。预先给予百日咳毒素会降低吗啡的最大抑制能力。一些细胞同时用吗啡和κ-阿片受体激动剂U50,488（1 - 5000微克/千克）进行测试：预先用百日咳毒素处理后，U50,488诱导的放电频率抑制显然未受影响。在未进行百日咳毒素预处理和预处理后观察到的阿片类药物对放电频率的抑制作用均可被纳洛酮逆转。因此，一种对百日咳毒素敏感的G蛋白可能介导吗啡对视上核假定的催产素神经元或其传入神经的抑制作用。
