Jensen J, Holmgren S
Department of Zoophysiology, University of Göteborg, Sweden.
J Comp Physiol B. 1992;162(2):184-8. doi: 10.1007/BF00398346.
The release of substance P-like immunoreactive material (SPLI) from the vascularly perfused stomach of the rainbow trout, Oncorhynchus mykiss, was studied. In most cases, SPLI was detected in the collected vascular perfusate during experimental resting conditions. Distensions of the stomach, accomplished by a water-filled intragastric balloon, produced an initial rapid relaxation of the stomach, followed by a slow further relaxation and a stimulation of contractile activity. The amount of SPLI in the vascular perfusate was significantly elevated during the distension period. Tetrodotoxin had no effect on the response to distension or on the release of SPLI during distension, indicating release from tetrodotoxin-insensitive neurons or endocrine cells. The results suggest that a substance P-like peptide may be involved in the contractile response and/or in the maintenance of muscular tone during gastric distensions in the rainbow trout. Infusion of capsaicin had no effect on the release of SPLI. However, capsaicin caused an increase in vascular flow, an effect that could be repeated on a second infusion of capsaicin, indicating that the action may not be specific to sensory neurons.
对虹鳟（Oncorhynchus mykiss）经血管灌注的胃中P物质样免疫反应性物质（SPLI）的释放进行了研究。在大多数情况下，在实验静息条件下收集的血管灌注液中检测到了SPLI。通过胃内充气球囊实现胃扩张，可使胃先迅速松弛，随后进一步缓慢松弛，并刺激收缩活动。在扩张期，血管灌注液中SPLI的量显著升高。河豚毒素对扩张反应或扩张期间SPLI的释放没有影响，表明其释放来自对河豚毒素不敏感的神经元或内分泌细胞。结果表明，一种P物质样肽可能参与虹鳟胃扩张时的收缩反应和/或肌肉张力的维持。注入辣椒素对SPLI的释放没有影响。然而，辣椒素会导致血管流量增加，第二次注入辣椒素时这种效应仍会出现，这表明该作用可能并非感觉神经元所特有。
