Uchida K
Nihon Yakurigaku Zasshi. 1983 Oct;82(4):223-35.
Pharmacological characteristics of the post-junctional adrenoceptors in the muscularis mucosae of the guinea-pig esophagus were examined in vitro. In the presence of propranolol (3 microM), all catecholamines, phenylephrine and methoxamine produced a weak contraction of the isolated muscularis mucosae. The order of potency of the contractile response was adrenaline greater than noradrenaline greater than methoxamine greater than phenylephrine and much weaker isoproterenol, dopamine and clonidine. The contractile responses to noradrenaline (10 microM) and adrenaline (10 microM) were markedly inhibited by phentolamine (3 microM), prazosin (3 microM), indomethacin (1 microM), aspirin (100 microM) and polyphloretin (30 microM), and slightly by yohimbine (3 microM). On the other hand, all catecholamines and terbutaline produced relaxation of the isolated muscularis mucosae which was maximally contracted with carbachol (3 microM) in the presence of phentolamine (10 microM), in a concentration-dependent manner. The order of potency of the inhibitory response was isoproterenol greater than noradrenaline greater than adrenaline and much weaker terbutaline and dopamine. The inhibitory responses to catecholamines were competitively antagonized by three beta blockers, being in the following order of potency as estimated by their pA2 values: propranolol greater than atenolol much greater than butoxamine. The pretreatment of the tissue with indomethacin (1 microM) did not modify the inhibitory responses to catecholamines. These results suggest that the guinea-pig esophageal muscularis mucosae has excitatory alpha 1 adrenoceptors and inhibitory beta 1 adrenoceptors, and the alpha 1, but not beta 1, adrenoceptors may link with the endogenous arachidonic acid cascade.
在体外研究了豚鼠食管黏膜肌层中节后肾上腺素能受体的药理学特性。在普萘洛尔（3微摩尔）存在的情况下，所有儿茶酚胺、去氧肾上腺素和甲氧明均可使离体黏膜肌层产生微弱收缩。收缩反应的效价顺序为肾上腺素＞去甲肾上腺素＞甲氧明＞去氧肾上腺素，而异丙肾上腺素、多巴胺和可乐定的作用则弱得多。去甲肾上腺素（10微摩尔）和肾上腺素（10微摩尔）引起的收缩反应被酚妥拉明（3微摩尔）、哌唑嗪（3微摩尔）、吲哚美辛（1微摩尔）、阿司匹林（100微摩尔）和聚黄酮（30微摩尔）显著抑制，被育亨宾（3微摩尔）轻度抑制。另一方面，在酚妥拉明（10微摩尔）存在的情况下，所有儿茶酚胺和特布他林均可使预先用卡巴胆碱（3微摩尔）最大程度收缩的离体黏膜肌层以浓度依赖的方式舒张。抑制反应的效价顺序为异丙肾上腺素＞去甲肾上腺素＞肾上腺素，特布他林和多巴胺的作用则弱得多。三种β受体阻滞剂竞争性拮抗儿茶酚胺引起的抑制反应，根据其pA2值估计，效价顺序为：普萘洛尔＞阿替洛尔＞丁氧胺。用吲哚美辛（1微摩尔）预处理组织并未改变对儿茶酚胺的抑制反应。这些结果表明，豚鼠食管黏膜肌层具有兴奋性α1肾上腺素能受体和抑制性β1肾上腺素能受体，且α1而非β1肾上腺素能受体可能与内源性花生四烯酸级联反应相关。
