回肠环肌和纵肌收缩反应的对比观察

在豚鼠和家兔分离与未分离的环肌和纵肌标本上,对比观察它们对电刺激和化学刺激反应的区别,分析参与活动的受体。主要结果①在分离和未分离纵肌之间未见明显的区别,对两种刺激均发生收缩反应;而分离和未分离环肌则有明显的区别,前者对两种刺激均不反应,后者都发生收缩,提示环肌的收缩有赖纵肌-肌间神经丛的存在。②在豚鼠回肠纵肌上含M受体和α_1受体,环肌上除M受体外,尚有N受体,未见α受体;兔的纵肌上以M和α_2受体为主,在环肌上未见此两类受体。

Comparative Observation on Contractile Responses of Circular And-Longitudinal Muscle of Guinea-pig And Rabbit Ileums

The contractile responses of circular muscle strips (separated as well as unse-parated) and longitudinal muscle strips (separated as well as unscparated) from guinea-pig and rabbit ileums induced by electrical and chemical stimulations were observed and compared. The role of related receptors in these responses was analysed. (1) Either separated or unseparated longitudinal muscle strips responded to the two kinds of stimulations significantly and similarly. There are significant differences in the responses of separated and unseparated circular muscle. While the oeparated circular muscle stips didn't respond to the two kinds of stimulation, the unseparated ones responded remarkably. This suggests that the contractile responses of circular muscle depend on the coupling of myenteric plexus-longitudinal muscle. (2) On the basis of the results, it is suggested that there are M-recep-tors and an-receptors on the longitudinal muscle and there are not only M-receptors but also N-receptors, but not any a-receptors, on the circular muscle of guinea pig ileum. There are M-receptors and a2-receptoes on the longitudinal muscle, but neither of them exists on the circular muscle of rabbit ileum.