School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
Urology. 2010 Nov;76(5):1267.e7-12. doi: 10.1016/j.urology.2010.06.040.
To examine the contractility of urothelium-intact (+UE) and urothelium-denuded (-UE) rat detrusor strips under adenosine triphosphate (ATP) treatment. Purinergic signaling exists in the bladder but both the inhibitory effect of ATP on detrusor contractions and the function of urothelial ATP are not established.
Detrusor strips were obtained from bladders of young adult rats. Isometric tension from both transverse and longitudinal contractions was measured using a myograph. The muscarinic agonist carbachol (CCh) was used to induce contractions, which were under the influences of different concentrations of ATP.
In both +UE and -UE strips, 1 mM ATP suppressed CCh-induced contractions. In longitudinal contractions, ATP added to the inhibitory effect of urothelium on CCh responses. Removal of the urothelium, but with exogenous ATP added, recovered the CCh responses to the same level as in +UE strips with no added ATP. Transverse contractions were less susceptible to ATP in the presence of urothelium.
We showed that the urothelium and ATP suppressed CCh-induced contractions to a similar extent. The findings suggest an inhibitory role of urothelial ATP in mediating detrusor smooth muscle contractility, which may be impaired in diseased bladders.
研究在三磷酸腺苷（ATP）处理下，完整尿路上皮（+UE）和去上皮尿路上皮（-UE）大鼠逼尿肌条的收缩性。膀胱中存在嘌呤能信号传导，但ATP 对逼尿肌收缩的抑制作用和尿路上皮 ATP 的功能尚未确定。
从年轻成年大鼠的膀胱中获得逼尿肌条。使用肌描记器测量横向和纵向收缩的等长张力。使用毒蕈碱激动剂卡巴胆碱（CCh）诱导收缩，在不同浓度 ATP 的影响下进行收缩。
在+UE 和-UE 条带中，1mM ATP 抑制了 CCh 诱导的收缩。在纵向收缩中，ATP 增强了尿路上皮对 CCh 反应的抑制作用。去除尿路上皮，但添加外源性 ATP，可使 CCh 反应恢复到与无外加 ATP 的+UE 条带相同的水平。存在尿路上皮时，横向收缩对 ATP 的敏感性降低。
我们表明尿路上皮和 ATP 以相似的程度抑制 CCh 诱导的收缩。这些发现提示尿路上皮 ATP 在调节逼尿肌平滑肌收缩性方面发挥抑制作用，而在患病膀胱中可能会受到损害。
