牵张负荷对豚鼠膀胱ICCs细胞内钙波的影响

Effect of stretch load on calcium wave of interstitial cells of Cajal in guinea pig bladder

目的探讨牵张负荷对豚鼠膀胱起搏细胞（interstitial cells of Cajal，ICCs）兴奋性的影响。方法胶原酶消化豚鼠膀胱，于特制的牵张培养皿中体外培养膀胱起搏细胞，激光共聚焦技术检测Fluo-4负载的起搏细胞在牵张负荷下Ca^2＋信号的变化。结果以豚鼠膀胱组织铺片及体外培养细胞中观察到c—kit染色阳性及长梭形有突起的细胞鉴定为膀胱起搏细胞，即ICCs细胞。细胞于牵张膜上培养4～5d后，予Fluo-4钙负载染色，激光共聚焦下检测，无应力状态时，ICCs细胞可观察到周期性的“钙波”，且其平均荧光强度显著强于平滑肌细胞（P〈0．05）。当牵张膜被动拉伸延长20％时，ICCs细胞先于平滑肌细胞发生钙波增强现象。结论静息状态下ICCs细胞可出现周期性钙波，牵张负荷可兴奋ICCs细胞。

Objective To explore the regulation of stretch load on the interstitial cells of Cajal （ICCs, pacemaker cells） in guinea pig bladder. Methods Cells were isolated by collagenase digestion and were cultured in special stretch plate. [ Ca^2＋ ] variation was assessed on Fluo-4 NW dye loaded cells undergoing stretch load or ease state using confocal laser scanning microscopy. Results c-kit positive ICCs were identified with lateral branches in both cultured plate and whole mounted bladder samples. After 4 -5 days＇ culture, cells were loaded with fluo-4 NW dye. Intermit calcium waves were found in ICCs. The mean fluorescence intensity of calcium waves in ICCs was higher than that in the smooth muscle cells （P 〈 0.05 ）. The [ Ca^2＋ ] in ICCs was significantly increased after stretch load and this change was initiated earlier than that in smooth muscle cells. Conclusion Cultured ICCs have periodical calcium wave, and facilitate calcium signals in response to stretch load.