机械牵张对豚鼠膀胱组织Cajal间质细胞形态学及兴奋性的影响

目的 探讨机械牵张对豚鼠膀胱组织Cajal间质细胞(ICC)形态及兴奋性的影响.方法 建立雌性豚鼠膀胱颈部分梗阻(PBOO)模型作为实验组.并设假手术组作为对照.术后4周取膀胱组织制片,免疫荧光染色观察2组ICC形态和分布情况;胶原酶消化豚鼠膀胱制细胞悬液,免疫荧光标记,流式细胞仪检测2组c-kit阳性细胞比率.在弹性硅胶膜七原代培养膀胱ICC,利用Fluo-4钙荧光指示剂检测机械牵张对ICC钙信号的影响.结果 2组豚鼠膀胱组织铺片均可见c-kit染色阳性典型长梭形有突起的ICC,主要分布于平滑肌肌束间;PBOO组膀胱平滑肌间质增厚,c-kit染色阳性细胞数量及其突起明显增多,互相连接呈网络状;PBOO组c-kit阳性细胞比率为(6.7±1.7)%,显著高于对照组的(1.0±0.5)%,差异有统计学意义(P＜0.05).体外培养的ICC可检测到自发性钙波,机械牵张刺激可诱导ICC发生钙波增强现象.结论 机械牵张可诱导膀胱ICC兴奋性增强;PBOO膀胱组织中ICC数量及相互联系显著增多.ICC可能参与了膀胱牵张感受功能并在长期牵张应力负荷下发生一定的适应性改变.

Effect of mechanical stretch on the interstitial cells of Cajal in guinea pig bladder

Objective To explore the variation of interstitial cells of Cajal(ICC)in morphology,quantity and distribution in guinea pig bladder with long-term mechanical stretch model after partial bladder outflow obstruction(PEOO)and the excitability of cultured ICC under substrate mechanical stretch in vitro.Methods Morphology and distribution of ICC in PBOO bladder were examined with immunofluorescent staining for c-kit.Moreover,cells dispersed with collagenase from both PBOO and control guinea pig bladder were stained with c-kit fluorescent antibody and the ratio of c-kit positive cells were evaluated by flow-eytometry.Primary cultured ICC were adherent on a flexible silicone membrane and mechanical stretch was obtained by extension the membrane stepwise and the excitability of cultured ICC were visualized by preloading Fluo-4 AM indicator and measured by confoeal microscopy.Results C-kit positive ICCs were confirmed by lateral branches in both controI and PBOO bladder samples,which was mainly distributed interspaced between muscle bundles.ICC in PBOO bladders had more dendritic branches and mutual connections to form a network.Meanwhile,the ratio of c-kit positive cells was increased by(6.7±1.7)%in PBOO bladder comparing to(1.0±0.5)%in control bladder with flow-cytometry counting.Cultured cells with fusiform dendritic branches and c-kit positive markers were identified as ICC which possessed spontaneous calcium waves.They showed enhanced calcium transients in respond to substrate mechanical stretch.Conclusion Cultured ICC owns features of stretch sensor in urinary bladder and ICCs increasing in number and interconnection in PBOO bladders suggests its adaptive role in guinea pig bladder after long-term mechanical stretch.