Cajal间质细胞在输尿管平滑肌自发性收缩中的作用

Role of interstitial cells of Cajal in spontaneous contraction of smooth muscles in guinea pig ureter

目的通过Glivec特异性地阻断Cajal间质细胞后观察豚鼠输尿管平滑肌肌条自发性收缩活动的变化,从功能学上探讨Cajal间质细胞在输尿管平滑肌自发性收缩中的作用。方法采用c-kit免疫荧光化学染色,激光共聚焦显微镜观察豚鼠输尿管组织内的ICCs;通过离体肌条实验观察特异性地阻断ICCs后豚鼠输尿管平滑肌肌条自发性收缩的变化。结果c-kit免疫荧光染色显示,在豚鼠输尿管组织中存在c-kit阳性的ICCs。在2.0g的前负荷下,终浓度为2×10-2mol/L的KCl可诱发对照组肌条出现稳定的自发性收缩,自发性收缩的波幅为(0.1045±0.0216)g,频率为(6.8±1.6)次/min;实验组经终浓度为10-4mol/L Glivec孵育30min后,再给予终浓度为2×10-2mol/L的KCl不能诱发肌条出现明显自发性收缩,更换Kreb's液洗脱Glivec30min后,肌条又恢复了自发性收缩,但收缩幅度略有降低。结论输尿管的ICCs在输尿管平滑肌的自发性收缩中起着重要作用,极有可能是输尿管的起搏细胞。

Objective To explore the effects of interstitial cells of Cajal in the ureter on the spontaneous contraction of smooth muscles.Methods The interstitial Cajal cells of ureter tissue were identified by c-kit immunofluorescence and laser scanning confocal microscopy.Smooth muscle strips were used to study the effect of Glivec on the spontaneous contraction of smooth muscles in vitro.Results By using immunofluorescence staining,c-kit-positive,ICC-like cells were found in the ureter of guineapigs.With a preload of 2.0 g, KCl （final concentration 2 ×10-2mol/L） induced stable spontaneous contraction in the smooth muscle strips of control group. The frequency of spontaneous contraction was （6.8±1.6） times/rain, and the amplitude was （0. 104 5±0. 021 6） g. After the smooth muscle strips of experiment group were incubated with Glivec （final concentration 10-4mol/L） for 30 rain, KC1 （final concentration 2 ×10-2mol/L） was added into them, but didn＇ t induce spontaneous contraction. Then the Glivec Kreb＇ s solution was substituted with normal Kreb＇ s solution without Glivec. After 30 rain, the spontaneous contractions reoccurred in the muscle strips with a slightly decreased amplitude. Conclusion ICC-like cells of smooth muscles, which play a very important role in the spontaneous contraction of guinea-pig ureter, are most likely to be the pacemakers of ureter.