γ-氨基丁酸增强人类肛管内括约肌的张力。

gamma-Aminobutyric acid enhances the tone of human internal anal sphincter.

作者信息

Kusunoki M, Shoji Y, Sakanoue Y, Yanagi H, Fujita S, Yamamura T, Utsunomiya J

机构信息

Second Department of Surgery, Hyogo College of Medicine, Japan.

出版信息

J Surg Res. 1991 Oct;51(4):293-6. doi: 10.1016/0022-4804(91)90110-8.

DOI:10.1016/0022-4804(91)90110-8

PMID:1656145

Abstract

The effect of gamma-aminobutyric acid (GABA) on the human internal anal sphincter was investigated. Cumulative applications of GABA produced concentration-dependent contractions (10(-8)-10(-5) M) of the isolated human sphincter. Pretreatment with bicuculline (GABAA antagonist) turned them to relaxation. Muscimol, a GABAA agonist, induced concentration-dependent contractions (10(-8)-10(-5) M); however, baclofen (GABAB agonist, 10(-8)-10(-5) M) promoted concentration-dependent relaxation of the strips. These results suggested that both excitatory GABAA receptors and inhibitory GABAB receptors exist in the internal anal sphincter. Oral administration of sodium valproate (1600 mg/day), a GABA transaminase inhibitor, enhanced the anal canal resting pressure in 10 normal volunteers. Anal manometry showed a significant elevation in tonus without affecting amplitudes or frequencies. These results indicated that endogenous GABA, which was increased by sodium valproate, produced elevations in the anal canal resting pressure through its specific receptors in the human internal anal sphincter.

摘要

研究了γ-氨基丁酸（GABA）对人肛门内括约肌的作用。对分离出的人括约肌累积应用GABA可产生浓度依赖性收缩（10⁻⁸ - 10⁻⁵M）。用荷包牡丹碱（GABAA拮抗剂）预处理后，这些收缩转变为松弛。GABAA激动剂蝇蕈醇可诱导浓度依赖性收缩（10⁻⁸ - 10⁻⁵M）；然而，GABAB激动剂巴氯芬（10⁻⁸ - 10⁻⁵M）可促进条带的浓度依赖性松弛。这些结果表明，肛门内括约肌中同时存在兴奋性GABAA受体和抑制性GABAB受体。10名正常志愿者口服GABA转氨酶抑制剂丙戊酸钠（1600毫克/天）可提高肛管静息压。肛门测压显示张力显著升高，而不影响幅度或频率。这些结果表明，丙戊酸钠增加的内源性GABA通过其在人肛门内括约肌中的特定受体使肛管静息压升高。