甘丙肽在豚鼠小肠胆碱能传递中的作用部位。

Site of action of galanin in the cholinergic transmission of guinea pig small intestine.

作者信息

Akehira K, Nakane Y, Hioki K, Taniyama K

机构信息

Department of Surgery II, Kansai Medical School, Moriguchi, Japan.

出版信息

Eur J Pharmacol. 1995 Sep 15;284(1-2):149-55. doi: 10.1016/0014-2999(95)00393-y.

DOI:10.1016/0014-2999(95)00393-y

PMID:8549619

Abstract

The mode and site of action of galanin were examined in the guinea pig small intestine. Galanin (3 x 10(-9)-10(-7) M) inhibited the twitch contractions of longitudinally and circularly oriented muscle strips mediated by the stimulation of cholinergic neurons, but not the contractions mediated by direct stimulation of smooth muscle cells with carbachol. Galanin (3 x 10(-9)-10(-7) M) inhibited both the electrically stimulated and the tetrodotoxin-resistant high K+ (40 mM)-induced increase of [3H]acetylcholine outflow from the ileal strips preloaded with [3H]choline, in a concentration dependent fashion. The inhibitory effect of galanin was antagonized by galantide and produced self-desensitization. The spontaneous and stimulated outflow of [3H]noradrenaline and [3H]gamma-aminobutyric acid were not affected by galanin even at 10(-7) M. Thus, galanin inhibits the motility of guinea pig ileum by inhibition of acetylcholine release from the enteric cholinergic neurons. Galanin may act on the specific receptor located on soma-dendritic regions and nerve terminals of cholinergic neurons.

摘要

在豚鼠小肠中研究了甘丙肽的作用方式和作用部位。甘丙肽（3×10⁻⁹ - 10⁻⁷ M）抑制由胆碱能神经元刺激介导的纵向和环向肌条的抽搐收缩，但不抑制用卡巴胆碱直接刺激平滑肌细胞介导的收缩。甘丙肽（3×10⁻⁹ - 10⁻⁷ M）以浓度依赖性方式抑制电刺激和对河豚毒素耐受的高钾（40 mM）诱导的、来自预先加载[³H]胆碱的回肠肌条的[³H]乙酰胆碱流出增加。甘丙肽的抑制作用被加兰他敏拮抗并产生自身脱敏。即使在10⁻⁷ M时，甘丙肽也不影响[³H]去甲肾上腺素和[³H]γ-氨基丁酸的自发和刺激流出。因此，甘丙肽通过抑制肠胆碱能神经元释放乙酰胆碱来抑制豚鼠回肠的运动。甘丙肽可能作用于位于胆碱能神经元胞体-树突区域和神经末梢上的特异性受体。