腺苷三磷酸对大鼠离体胃平滑肌运动的影响

目的观察腺苷三磷酸(ATP)对大鼠离体胃平滑肌运动的调节作用。方法制备大鼠离体胃体纵行肌、胃体环行肌、胃窦纵行肌、胃窦环行肌标本,观察ATP(01,1,10,100μmol·L-1和1mmol·L-1)的作用。结果在胃体纵行肌标本,ATP诱发微弱的舒张反应,继而出现收缩反应;在高钾预收缩条件下,ATP则引起较大舒张反应后续较小的收缩反应。ATP对胃体环行肌诱发单相收缩反应。1~100μmol·L-1ATP抑制胃窦纵行肌的自发性收缩幅度,同时加快收缩频率;1mmol·L-1ATP则完全抑制自发性收缩反应;在高钾预收缩条件下,ATP产生浓度依赖性舒张反应。1~10μmol·L-1ATP先增大后减低胃窦环行肌的自发性收缩幅度,同时加快收缩频率;100μmol·L-1~1mmol·L-1ATP则抑制自发性收缩反应。结论本文首次报道了ATP影响大鼠离体胃体纵行肌、胃体环行肌、胃窦纵行肌、胃窦环行肌四种平滑肌的运动,且对各种标本的作用特点互不相同,提示ATP在生理条件下对大鼠胃的运动功能发挥重要的调节作用。

Effects of adenosine triphosphate on motility of isolated gastric smooth muscle in rats

Aim To observe the modulation of adenosine triphosphate (ATP) on motility of isolated gastric smooth muscle from rat.Methods Longitudinal and circular muscle strips of rat gastric body and antrum were prepared, and the effects of ATP (0.1, 1,10,100 μmol·L~-1 and 1 mmol·L~-1 ) on the motility of the strips were investigated. Results ATP induced a small relaxation followed by an obvious spasm in longi- tudinal muscle strips of the gastric body; when tone was raised by KCl, ATP induced a larger relaxation followed by a smaller spasm.ATP only produced contraction in circular muscle strips of the gastric body.Low concentration of ATP inhibited the contractile amplitude of the antral longitudinal strips, at the same time increased the frequency of the contraction apparently; when tone was raised by KCl, ATP produced a concentration-related relaxation.Low concentration of ATP firstly enhanced and then inhibited contractile amplitude of antral circular musle strips, while high concentration of ATP fully inhibited the motility. Conclusion We firstly reported the obvious effects of ATP on longitudinal and circular strips of rat gastric body and antrum. The effects of ATP on the four preparations were different from each other, suggesting that ATP plays an important modulatory role on motility of gastric smooth muscle of rats.