Weiss Robert M, Tamarkin Frank J, Wheeler Marcia A
Section of Urology, Yale University School of Medicine, New Haven, Conneticut 06520-8041, USA.
J Smooth Muscle Res. 2006 Aug;42(4):103-15. doi: 10.1540/jsmr.42.103.
Ureteral peristaltic activity begins with the origin of electrical activity at pacemaker sites. These sites are located in the proximal portion of the urinary collecting system. The 'atypical' smooth muscle cells at these sites fire 'pacemaker' potentials at a frequency higher than the 'driven' action potentials recorded from typical smooth muscle cells. In contrast to typical smooth muscle cells, these atypical pacemaker cells have less than 40% of their cellular area occupied by contractile filaments and demonstrate a sparse immunoreactivity for alpha-smooth muscle actin. Expression of c-Kit, a tyrosine kinase receptor, correlates with the onset of organized ureteral peristalsis in the embryo. Capsaicin-sensitive sensory afferents and the endogenous release of tachykinins and prostaglandins are involved in the maintenance of normal ureteral peristalsis.
输尿管蠕动活动始于起搏点的电活动起源。这些位点位于尿液收集系统的近端部分。这些位点的“非典型”平滑肌细胞以高于从典型平滑肌细胞记录的“驱动”动作电位的频率发放“起搏”电位。与典型平滑肌细胞不同，这些非典型起搏细胞的细胞面积中收缩丝所占比例不到40%，并且对α-平滑肌肌动蛋白的免疫反应性较弱。酪氨酸激酶受体c-Kit的表达与胚胎中输尿管有组织蠕动的开始相关。辣椒素敏感的感觉传入神经以及速激肽和前列腺素的内源性释放参与了输尿管正常蠕动的维持。
