特集名 | 消化管機能と受容体 -- 臨床とのかかわり | |
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題名 | ドーパミン受容体 | |
発刊年月 | 2000年 04月 | |
著者 | 永原 章仁 | 順天堂大学医学部消化器内科 |
【 要旨 】 | ドーパミンアゴニストの消化管に対する作用は,ドーパミン受容体やコリン作動性神経を介して消化管運動を減弱させ,血管平滑筋上あるいは交感神経節後線維上のドーパミン受容体に作用し血流を増加させる.また,D1受容体刺激により胃酸分泌は抑制され,胃粘膜防御は促進される.さらに,胃癌,大腸癌でのドーパミン受容体の変化や,細胞増殖を抑制的に調節し,発癌にも関与していることが明らかにされつつある.広く臨床に用いられているD2受容体アンタゴニストであるdomperidone,sulpiride,metoclopramideはCTZ(chemoreceptort rigger zone)と胃に存在するD2受容体に作用し制吐作用,消化管運動促進作用を示すとともに抗潰瘍作用を発揮すると考えられている. |
Theme | The Role of Receptors in Gastrointestinal Functions | |
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Title | Dopamine Receptors | |
Author | Akihito Nagahara | Department of Gastroenterology, Juntendo University, School of Medicine |
[ Summary ] | It is known that dopamine receptors have 5 receptor subtypes, which are known as D1, D2, D3, D4 and D5 receptor subtypes. D1 and D2 receptor subtypes play important roles in the gastrointestinal tract. Dopaminergic compounds act on the gastrointestinal tract through these dopamine receptors. The role of dopamine agonists in the gastrointestinal tract, through dopamine receptors introduces many events;attenuate gastric motility, increased gastrointestinal blood flow and improved gastric mucosal microcirculation, reduced gastric acid secretion and increased gastroprotective activity. Moreover, significant alterations of dopamine receptors in gastric and colon carcinoma are reported. Dopamine receptor agonists also regulate mucosal proliferation, which may have a correlation with carcinogenesis. In widely clinical use, D2 receptor antagonists, such as domperidone, sulpiride and metoclopramide improve cases of nausea, gastrointestinal dysmotility and gastroduodenal ulcers through blocking D2 receptors, which are located in the chemoreceptor trigger zone in the brain and in the stomach. |