对5-羟色胺抑制豚鼠回肠中γ-氨基丁酸诱导的胆碱能收缩作用机制的重新评估。

A re-appraisal of the mode of action of 5-HT in inhibiting GABA-induced cholinergic contractions in the guinea-pig ileum.

作者信息

Tonini M, Saltarelli P, Onori L, De Ponti F, Garlaschelli L, Rizzi C A, Crema A

出版信息

Eur J Pharmacol. 1986 Aug 15;127(3):267-70. doi: 10.1016/0014-2999(86)90373-0.

PMID:3019731

Abstract

In the guinea-pig ileum, pretreatment with 5-hydroxytryptamine (5-HT) (5 microM) for 4-5 min inhibited both 5-HT- and gamma-aminobutyric acid (GABA)-induced cholinergic contractions without consistently altering those induced by electrical field stimulation. Cisapride (1 micron) antagonized 5-HT-induced cholinergic contractions but left those induced by GABA or twitch responses unchanged. These results indicate that the 5-HT action in inhibiting GABA-induced cholinergic responses may arise at the interneuronal level, thus suggesting that GABA may also indirectly activate cholinergic terminal neurons. These findings rule out the possibility of 5-HT acting as an intermediate transmitter in this type of response.

摘要

在豚鼠回肠中，用5-羟色胺（5-HT）（5微摩尔）预处理4-5分钟，可抑制5-HT和γ-氨基丁酸（GABA）诱导的胆碱能收缩，而对电场刺激诱导的收缩无持续影响。西沙必利（1微摩尔）可拮抗5-HT诱导的胆碱能收缩，但对GABA诱导的收缩或抽搐反应无影响。这些结果表明，5-HT抑制GABA诱导的胆碱能反应的作用可能发生在中间神经元水平，因此提示GABA也可能间接激活胆碱能终末神经元。这些发现排除了5-HT在这类反应中作为中间递质的可能性。