The basic research for the novel treatment for under active bladder -focusing on the construction of troponin system in smooth muscle-

一般认为，在平滑肌收缩过程中，MLCK系统而非肌钙蛋白系统起主导作用。然而，我们在膀胱平滑肌中发现了心肌肌钙蛋白T（cTnT），因此，本研究旨在阐明平滑肌肌钙蛋白亚基，并探讨利用逼尿肌平滑肌进行临床治疗的可能性。肌钙蛋白由3个亚基（T、I和C）组成，并分为3组（心肌、慢骨骼肌、快骨骼肌）。我们检测了所有肌钙蛋白亚基，并阐明了不仅所有类型的TnT，而且慢骨骼肌型肌钙蛋白I在人逼尿肌中的表达。此外，与其他平滑肌器官相比，其基因的显性表达被识别。平滑肌特异性蛋白calponin和caldesmon也在蛋白水平表达，提示肌钙蛋白亚基及其蛋白结合的新型收缩系统。

It has been generally accepted that in smooth muscle contraction, MLCK system but not troponin system is dominant. However, we found cardiac troponin T (cTnT) in urinary bladder smooth muscle.The following present study was thus designed in order to clarify troponin subunits in smooth muscle and to explore the possibility for clinical treatment using detrusor smooth muscle. Troponin is composed of 3 subunits (T, I, and C), and categorized into 3 groups (cardiac, slow skeletal muscle, fast skeletal muscle). We examined all troponin subunits and clarified the expression of not only all types of TnT but also slow skeletal muscle type of troponin I in human detrusor. Further, dominant expression of their genes were recognized compared to other smooth muscle organs. The smooth muscle specific protein, calponin and caldesmon were also expressed at protein level suggesting novel contraction system combined with troponin subunits and their protein.