蚯蚓背肌胆碱能受体的药理学性质及梭曼直接作用的进一步证实

THE PHARMACOLOGICAL PROPERTIES OF THE CHOLINERGIC RECEPTOR AND THE FURTHER EVIDENCES OF THE DIRECT ACTION OF SOMAN ON THE EARTHWORM DORSAL MUSCLE

我们曾报道梭曼(GD)在蚯蚓背纵肌上的肌收缩效应可以通过生化膜处理方法或药理学受体阻断方法与乙酰胆碱(ACh)效应区别开。说明梭曼有一个胆碱能受体(ChR)以外的特殊作用部位,暂假定为“梭曼受体”。究竟蚯蚓背纵肌上这种与梭曼直接肌收缩效应无关的ChR具有什么样的药理学性质,是-烟碱(N)-ChR,还是毒蕈碱(M)-ChR,或者是N-M混合型ChR,这方面还无明确的文献报导。

In this paper,the pharmacological properties of the cholinergic receptor on the earthworm(Eisenia foetida)dorsal longitudinal muscle were studied and the noncholinergic receptor effect of soman was confirmed further.Pilocarpine 10M,arecoline 10M and oxotremorine 10M did not induce contractions of the earthworm dorsal longitudinal muscle.Nicotine 10M induced the contraction of the muscle.The contraction of the muscle elicitated by ACh 10M was not abolished by atropine 10M or by hexamethonium 10M but could be strongly inhibited by D-tubocurarine 2.75×10M and irreversibly blocked by pure cobratoxin 0.2mg/ml.The hydrolytic products of soman,fluoride and pinacolyl methyphosphonate did not show any effect on the muscle preparation.On the preparation poisoned by cobratoxin,as ACh effect disapperaed entirely,soman was still able to cause the contraction of the muscle.The results indicated that the ChR on the earthworm dorsal longitudinal muscle resembles the N-ChR in the neuromuscular junction of vertebrate animal,We surmise that the contraction of the muscle elicitated by soman does not relate to the hydrolytic products of soman and that the"soman receptor"does not relate to N-ChR.