Jodal M, Holmgren S, Lundgren O, Sjöqvist A
Department of Physiology, University of Göteborg, Sweden.
Gastroenterology. 1993 Nov;105(5):1286-93. doi: 10.1016/0016-5085(93)90130-5.
The enteric nervous system is responsible in vivo for most of the change in fluid transport induced by cholera toxin. The aim of the present study was to investigate the importance of the myenteric plexus in the Intramural reflex responsible for this secretion.
Long-term ablation of the myenteric plexus was achieved by serosal application of benzalkonium chloride on jejunal segments in rats.
The treated segments without functioning myenteric plexus showed a normal net fluid absorption. Cholera toxin in this segment only induced a reduction of fluid absorption, whereas in a nontreated ileal segment it concomitantly induced a conspicuous net fluid secretion. Intravenous hexamethonium did not change the cholera toxin response in the treated jejunal segments, whereas vasoactive intestinal polypeptide elicited a marked secretion.
Benzalkonium chloride treatment eliminated the ability of cholera toxin to induce intestinal secretion. Thus, all afferent fibers in the intramural secretory reflex activated by cholera toxin are probably conveyed via the myenteric plexus, which functions as the integrating center in the enteric nervous system. The Ussing chamber technique using stripped intestinal preparations cannot be used when studying effects of luminal secretagogues.
在体内，肠神经系统负责霍乱毒素诱导的大部分液体转运变化。本研究的目的是探讨肌间神经丛在负责这种分泌的壁内反射中的重要性。
通过在大鼠空肠段浆膜上应用苯扎氯铵实现肌间神经丛的长期消融。
无功能肌间神经丛的处理段显示出正常的净液体吸收。该段中的霍乱毒素仅诱导液体吸收减少，而在未处理的回肠段中，它同时诱导明显的净液体分泌。静脉注射六甲铵未改变处理过的空肠段对霍乱毒素的反应，而血管活性肠肽引起明显的分泌。
苯扎氯铵处理消除了霍乱毒素诱导肠道分泌的能力。因此，霍乱毒素激活的壁内分泌反射中的所有传入纤维可能通过肌间神经丛传导，肌间神经丛在肠神经系统中起整合中心的作用。在研究腔内促分泌剂的作用时，不能使用使用剥离肠段制备的尤斯灌流小室技术。
