牛蛙十二指肠中是否存在功能性胆碱能神经支配？

Is there functional cholinergic innervation in the frog duodenum (Rana catesbeiana)?

作者信息

Kitazawa T, Furuhashi H, Umezawa K, Morioka M, Temma K, Kondo H

出版信息

Comp Biochem Physiol C Comp Pharmacol Toxicol. 1986;85(2):275-82. doi: 10.1016/0742-8413(86)90194-5.

Abstract

To determine if functional cholinergic innervation occurs in the frog duodenum or not, the effects of exogenous acetylcholine and electrical transmural stimulation, the contractile activity of an acid extract from the frog duodenum, and the distribution of acetylcholinesterase (AChE) activity in the wall of the frog duodenum were investigated. Acetylcholine caused non-sustained contraction in a dose-dependent manner (100 nM-1 mM). The ED50 value was 17 +/- 2.4 microM. Atropine (500 nM) shifted the dose-response curve for acetylcholine parallel to the right. Transmural stimulation of the frog duodenum caused frequency-dependent (0.5-50 Hz) contraction which was not decreased by atropine (500 nM) at all. The acid extract from the frog duodenum caused contraction of a longitudinal muscle strip of guinea-pig ileum but atropine (500 nM) had no significant effect on the contraction. Only a little AChE activity was found in Auerbach's plexus of the frog duodenum compared with that of the rat ileum. These results suggest that a cholinergic nerve is present in the frog duodenum but its physiological significance is very small.

摘要

为了确定功能性胆碱能神经支配是否存在于青蛙十二指肠中，研究了外源性乙酰胆碱和电透壁刺激的作用、青蛙十二指肠酸提取物的收缩活性以及青蛙十二指肠壁中乙酰胆碱酯酶（AChE）活性的分布。乙酰胆碱以剂量依赖性方式（100 nM - 1 mM）引起非持续性收缩。ED50值为17±2.4 μM。阿托品（500 nM）使乙酰胆碱的剂量 - 反应曲线平行右移。青蛙十二指肠的透壁刺激引起频率依赖性（0.5 - 50 Hz）收缩，而阿托品（500 nM）对此收缩完全没有影响。青蛙十二指肠的酸提取物引起豚鼠回肠纵肌条收缩，但阿托品（500 nM）对该收缩没有显著影响。与大鼠回肠相比，在青蛙十二指肠的奥尔巴赫神经丛中仅发现少量AChE活性。这些结果表明青蛙十二指肠中存在胆碱能神经，但其生理意义非常小。