Paterson W G
Gastrointestinal Diseases Research Unit, Queen's University, Kingston, ON, Canada.
Can J Physiol Pharmacol. 1997 Jan;75(1):65-73.
To characterize the neuromuscular mechanisms responsible for control of esophageal longitudinal muscle function, in vivo and in vitro preparations of the intact opossum esophagus were studied using both miniature strain gauge transducers and a specially designed transducer that measured longitudinal axis movement of the entire esophagus. Esophageal shortening in response to swallowing was abolished by atropine in virtually all animals, whereas in 4 of 11 animals there was a significant noncholinergic component to shortening evoked by vagal efferent nerve stimulation. Balloon distention evoked atropine-sensitive esophageal shortening due to contractions occurring at and below the site of distention, which was then followed, upon balloon deflation, by noncholinergic longitudinal muscle contractions aboral to the balloon. A similar two-component response was recorded in response to electrical stimulation or balloon distention in vitro. Although the shortening occurring during stimulation was atropine sensitive, both components could be activated in the presence of tetrodotoxin. These studies indicate that the primary functional innervation to the opossum longitudinal muscle esophagus is cholinergic; noncholinergic and myogenic mechanisms are also demonstrable, but it is unclear whether they have a significant functional role.
为了描述负责控制食管纵肌功能的神经肌肉机制，我们使用微型应变片传感器和一种专门设计的用于测量完整负鼠食管纵轴运动的传感器，对完整负鼠食管的体内和体外标本进行了研究。在几乎所有动物中，阿托品都消除了吞咽引起的食管缩短，而在11只动物中的4只，迷走神经传出神经刺激引起的缩短存在显著的非胆碱能成分。球囊扩张引起阿托品敏感的食管缩短，这是由于在扩张部位及以下部位发生收缩所致，随后在球囊放气时，球囊口侧的非胆碱能纵肌收缩。在体外对电刺激或球囊扩张的反应中也记录到了类似的双成分反应。虽然刺激期间发生的缩短对阿托品敏感，但在存在河豚毒素的情况下，两种成分均可被激活。这些研究表明，负鼠食管纵肌的主要功能性神经支配是胆碱能的；非胆碱能和肌源性机制也可得到证实，但尚不清楚它们是否具有重要的功能作用。
