腸壁内在神経叢の生理学的意義

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This work was undertaken to clarify the physiological character of the intestinal inner plexus, especially of the post-ganglionic inhibitory nerve fibres which were found in relation to action of nicotine on intestinal motility, and to detect the association of the plexus with intestinal movement, above all, with peristaltic movement which plays the part of carrying contents of the intestine. (1) In action of nicotine (10^<-6>～10^<-4>g/ml) on motility of small intestine isolated from animals (dog, cat, rabbit, guinea-pig, rat and mouse) appeared a transient inhibitory response ("pre-inhibitory response") which was followed by a excitatory one, always in the rat and sometimes in the dog and rabbit but did not in the other animals. This "pre-inhibitory response" was abolished by ganglionic blocking agents (pentamethonium, C-5; hexamethonium, C-6; respectively 10^<-5>～10^<-4>g/ml) and in addition, by adrenergic blocking agents (choline 2,6 xylylether bromide, TM10; dichloroisoproterenol, DCI; respectively 10^<-5>～10^<-4>g/ml). This suggests that this "response" is stimulative effect of nicotine on ganglia in the inner plexus to cause excitation of post-ganglionic adrenergic nerve fibres. It may follow from this that in the rat there are two different kinds of post-ganglionic nerve fibres in the intestinal inner plexus, one being cholinergic (excitatory) nerve fibres which have been understood fully, and the other adrener-gic ("inhibitory") ones. (2) The physiological role of this "inhibitory nerve fibres" on intestinal movement was investigated electromyographically by taking, as an index, the number of "spike" discharge which has been described to correspond to the degree of intestinal activity. When a balloon in the intestinal lumen was swollen to give its wall a local distention which is said to be a factor of developing the peristaltic movement, the number of "spike" increased at the oral side and decreased or abolished at the anal side, of the most distended part of the wall. It is considered that the increase at the oral side shows an excitation of intestinal motility by cholinergic effect and the decrease at the anal side shows an inhibition by adrenergic effect, the latter effect being blocked by TM10. Therefore, the presence of excitatory and inhibitory nerve fibres in the plexus may be associated with local reflex in the intestinal wall or with the orientation of peristaltic movement which will carry the contents. (3) Also in the caecum of the chick, both post-ganglionic excitatory and inhibitory nerve fibres were found by pursuing histologically, physiologically and pharma-cologically the same response as found in the rat, under application of nicotine. Accordingly also in the chick, the presence of both fibres may be associated with the orientation of peristaltic movement which will carry the contents. (4) Furthermore, it was found that in the chick's caecum the excitatory nerve fibres were originated exclusively from Auerbach's ganglia and the inhibitory nerve fibres from Meissner's. This is an interesting fact that has never been discovered in mammalian intestines, a fact which was demonstrated by making mechanically Auerbach's and Meissner's ganglion-free preparations of the caecum and applying nicotine to both of these preparations.
大阪府立大学の論文
1969-03-31

腸壁内在神経叢の生理学的意義

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