Barthó L, Holzer P, Leander S, Lembeck F
Department of Pharmacology, Medical School, University of Pécs, Hungary.
Neuroscience. 1989;28(1):211-7. doi: 10.1016/0306-4522(89)90245-5.
It has previously been found that, in the presence of naloxone, the ganglionic blocking drug hexamethonium fails to completely block peristaltic motility in the isolated ileum of the guinea-pig. This hexamethonium-resistant peristaltic activity is coordinated by enteric nerves since it is abolished by tetrodotoxin. In the present study the neurotransmitter circuitry of this type of peristalsis was studied by means of specific antagonists. Atropine totally suppressed hexamethonium-resistant peristalsis. This type of peristalsis was also strongly inhibited by the tachykinin antagonist, spantide, if a concentration sufficient to antagonize neuronally located substance P receptors was employed. In contrast, the cholecystokinin antagonist, lorglumide, caused only a slight inhibition of hexamethonium-resistant peristalsis. Both substance P and the cholecystokinin-related peptide, ceruletide, potently stimulated the hexamethonium-resistant type of peristaltic activity. These data indicate that, after blockade of nicotinic acetylcholine receptors, tachykinins mediate neuroneuronal coordination of peristalsis whereas acetylcholine acting via muscarinic receptors may be primarily responsible for neuromuscular transmission. Cholecystokinin-like peptides appear to play a modulator rather than a mediator role in hexamethonium-resistant peristalsis.
先前已经发现，在纳洛酮存在的情况下，神经节阻断药物六甲双铵不能完全阻断豚鼠离体回肠的蠕动。这种对六甲双铵耐药的蠕动活动由肠神经协调，因为它可被河豚毒素消除。在本研究中，通过使用特异性拮抗剂研究了这种蠕动类型的神经递质回路。阿托品完全抑制了对六甲双铵耐药的蠕动。如果使用足以拮抗神经元定位的P物质受体的浓度，速激肽拮抗剂spantide也强烈抑制这种蠕动类型。相比之下，胆囊收缩素拮抗剂洛谷胺仅对六甲双铵耐药的蠕动产生轻微抑制。P物质和胆囊收缩素相关肽蛙皮素均强烈刺激六甲双铵耐药类型的蠕动活动。这些数据表明，在烟碱型乙酰胆碱受体被阻断后，速激肽介导蠕动的神经元间协调，而通过毒蕈碱受体起作用的乙酰胆碱可能主要负责神经肌肉传递。胆囊收缩素样肽在六甲双铵耐药蠕动中似乎起调节剂而非介质的作用。
