肾上腺素通过肾上腺素能β受体介导对离体大鼠结肠和十二指肠的抑制作用。

Depressive effect of epinephrine mediated via adrenergic beta-receptor in isolated rat colon and duodenum.

作者信息

Nakahata N, Nakanishi H, Suzuki T

出版信息

Jpn J Pharmacol. 1977 Jun;27(3):341-9. doi: 10.1254/jjp.27.341.

DOI:10.1254/jjp.27.341

PMID:199772

Abstract

Differences in sensitivity to catecholamines between colon and duodenum were examined in tissues from the rat, monitoring the depressive effect of catecholamines on contractile response to acetylcholine (ACh). The sensitivity of colonic tissue to ACh was higher than that of duodenal. Epinephrine (Ep, 10(-7) g/ml) depressed the contractile response to ACh in the colonic tissue, but not in the duodenal. The depressive effect of Ep on the contractile response to ACh is attributed to the stimulation of adrenergic beta-receptors in the colonic tissue as the depression disappeared by pretreatment with propranolol (10(-6) g/ml). There was no difference on the depressive effect of papaverine on the contractile response to ACh, except when low concentrations were used. Dibutyryl cyclic AMP (10(-4) g/ml) depressed the contractile responses of both tissues to ACh. After treatment with Ep (10(-7) g/ml), cyclic AMP content was increased in the colonic tissue but not in the duodenal. However, papaverine (3 X 10(-6 g/ml) and a higher dose of Ep(10(-6) g/ml) increased cyclic AMP content in both tissues. The increase of cyclic AMP and the decrease of tension caused by Ep were not correlated in these tissues. However, a positive correlation was observed between the depressive effect of Ep on the contractile response to ACh and the increase of cyclic AMP content in these tissues.

摘要

通过监测儿茶酚胺对乙酰胆碱（ACh）收缩反应的抑制作用，研究了大鼠结肠和十二指肠组织对儿茶酚胺敏感性的差异。结肠组织对ACh的敏感性高于十二指肠组织。肾上腺素（Ep，10⁻⁷ g/ml）可抑制结肠组织对ACh的收缩反应，但对十二指肠组织无此作用。Ep对ACh收缩反应的抑制作用归因于其对结肠组织中肾上腺素能β受体的刺激，因为用普萘洛尔（10⁻⁶ g/ml）预处理后这种抑制作用消失。除了使用低浓度时，罂粟碱对ACh收缩反应的抑制作用没有差异。二丁酰环磷腺苷（10⁻⁴ g/ml）可抑制两种组织对ACh的收缩反应。用Ep（10⁻⁷ g/ml）处理后，结肠组织中的环磷腺苷含量增加，而十二指肠组织中则没有。然而，罂粟碱（3×10⁻⁶ g/ml）和更高剂量的Ep（10⁻⁶ g/ml）可使两种组织中的环磷腺苷含量增加。在这些组织中，Ep引起的环磷腺苷增加和张力降低并无相关性。然而，在这些组织中，Ep对ACh收缩反应的抑制作用与环磷腺苷含量的增加呈正相关。