膀胱平滑肌细胞自发性钙活动传递的在体观察和分析

Visualization and analysis of propogation of spontaneous Ca^(2+) transients of smooth muscle cells in the rat bladder in situ

目的:观察离体活膀胱肌条铺片中平滑肌细胞自发性钙活动,并分析平滑肌细胞自发性钙活动的特征。方法:制作离体膀胱肌条铺片,Physiological saline生理液灌流保持肌条铺片活性。待肌条自发性收缩活动出现后,Fluo-4负载肌条铺片激光扫描共聚焦显微镜观察并高速扫描记录平滑肌细胞自发性钙活动,随后利用Fluoview软件分析平滑肌细胞自发性钙活动肌束内纵向、横向及肌束间的传递情况。结果:成功记录到离体活膀胱肌条铺片中平滑肌细胞的节律性自发性钙活动。钙活动在肌束内纵向传递几乎无时间延迟,但在肌束内横向传递有一定的时间延迟;在相邻的膀胱平滑肌束间也记录到钙活动的传递。结论:平滑肌细胞的自发性钙活动起源于肌束的一侧,随后传导到肌束的另一侧;平滑肌细胞钙活动纵向传递和横向传递的途径和机制可能不同;膀胱平滑肌束之间的钙活动传递可能是通过ICCs细胞完成。

Objective： To observe the propagation of spontaneous Ca〉 transients in smooth muscle cells （SMCs） and analysis its properties in the rat bladder in situ. Methods： Single layer of smooth muscle bundles attached to the serosal layer were prepared and superfused with warmed physiological saline to recover and maintain their activity. After spontaneous muscle movements of the tissues were visually detected, the muscle layers were loaded with the fluo-4 and then spontaneous Ca^2＋ transients of SMCs in the muscle layers were observed by conlbcal laser scanning microscopy. Spontaneous Ca^2＋ transients can propagate in the axial direction and transverse direction of smooth muscle bundles and between smooth muscle bundles of the rat bladder. Results： Spontaneous Ca〉 transients of SMCs in the smooth layers were successfully detected. Delay of propagation can be observed along the transverse direction but not along the axial direction. Propagations of spontaneous Ca^2＋ transients between smooth muscle bundles were also observed by confocal laser scanning microscopy. Conclusion： These results suggested that spontaneous Ca^2＋ transients originated almost simultaneously along the boundary of a smooth muscle bundle and then propagated to the other boundary. Mechanism of spontaneous Ca^2＋ transients＇ propogation along the transverse direction may be different from that along the axial direction. Spontaneous Ca^2＋ transients can propagate between smooth muscle bundles of the rat bladder via ICCs.