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目的腺苷三磷酸(ATP)对大鼠离体远端结肠纵行肌运动的影响已明确,对近端结肠纵行肌的影响可能不同,但未有报告,为此对此进行观察并探讨其受体机制。方法观察静息张力时或预收缩时0.1μmol·L-1～1mmol·L-1ATP和1～100μmol·L-1腺苷对大鼠近端结肠纵行肌的抑制和兴奋作用。结果在静息张力下,1μmol·L-1～1mmol·L-1ATP对大鼠近端结肠纵行肌产生3种效应,即抑制自发性收缩反应,一过性轻度降低基础张力(0.05～0.08g),随后产生浓度依赖性收缩反应(0.04～0.44g)。0.1μmol·L-1河豚毒素不影响ATP的上述作用。在静息张力下,1～100μmol·L-1腺苷对近端结肠纵行肌未产生明显的收缩反应。应用5羟色胺(5HT)或乙酰胆碱(ACh)预收缩标本时,1μmol·L-1～1mmol·L-1ATP产生明显的浓度依赖性舒张反应(23.2%～94.6%,5HT预收缩;24.8%～92.4%,ACh预收缩),而腺苷引起的舒张反应明显小于ATP。结论在大鼠离体近端结肠纵行肌,ATP主要通过嘌呤嘧啶(P)2受体介导收缩反应,部分通过P1受体介导舒张反应。
Aims The effect of adenosine triphosphate (ATP) on isolated longitudinal colon longitudinal muscle in rats has been clarified, and the effect on the longitudinal colon muscles of the proximal colon may be different, but no reports have been reported Its receptor mechanism. Methods The inhibitory and excitatory effects of 0.1μmol·L-1 ~ 1mmol·L-1 ATP and 1 ~ 100μmol·L-1 adenosine on the longitudinal colon of the proximal colon of rats during resting tension or precontraction were observed. Results Under resting tension, 1μmol·L-1 ~ 1mmol·L-1 ATP produced three kinds of effects on the longitudinal muscle of proximal colon in rats, that is, inhibition of spontaneous contractile responses, transient mild reduction of basal tension (0.05 ~ 0.08 g) followed by a concentration-dependent contractile response (0.04-0.44 g). 0.1μmol·L-1 tetrodotoxin did not affect the above-mentioned effects of ATP. Under resting tension, 1 ~ 100μmol·L-1 adenosine had no significant contractile response to the longitudinal colon of proximal colon. When pretreated with 5HT or ACh, 1μmol·L-1 ~ 1mmol·L-1ATP produced a significant concentration-dependent relaxation response (23.2% -94.6%, 5HT precontraction, 24.8% -92.4 %, ACh precontracted), while adenosine induced diastolic response was significantly less than ATP. Conclusions In the isolated rat proximal longitudinal colon muscle, ATP mediates the contractile response mainly through the purine pyrimidine (P) 2 receptor and partly through the P1 receptor.