细胞突触在稳定非梗阻性膀胱平滑肌中存在的证据

Evidence of occurrence of gap junctions in stable nonobstructed human bladder

目的研究正常人膀胱中细胞突触及其构成蛋白连接蛋白(Cx)是否存在。方法对6例全膀胱切除患者平滑肌用透射电子显微镜,冷冻爆裂电镜,逆转录聚合酶链反应(RT-PCR),免疫组化等方法进行研究。结果电镜结果显示膀胱平滑肌存在细胞突触,但这些细胞突触较小、形态不规律。RT-PCR 结果显示所有的样本均扩增出2个片段,大小分别为300 bp 和200 bp,测序结果显示它与已发表的 Cx45一致。荧光免疫组化显示大多数逼尿肌存在 Cx45的免疫信号。结论非梗阻性人膀胱平滑肌细胞是通过细胞突触进行电耦合的。

Objective To investigate the occurrence of gap junctions and the gap junction forming protein connexin （Cx） in normal human detrusor. Methods Specimens of detrusor smooth muscle were obtained from 6 patients with localized bladder tumors during radical cystectomy. Transmission electron microscopy and freeze fracture microscopy were used to observe the microstructure of the detrusor smooth muscle. Reverse transcription polymerase chain reaction （RT-PCR） and fluorescence immunohistochemistry was used to detect the expression of Cx in the detrusoe smooth muscle. Results Ultrastructural and freeze fracture studies showed gap junctions in the detrusor smooth muscle cells. However, these gap junctions appeared to be small and irregularly shaped. RT-PCR amplified 2 fragments with the lengths of 300 bp and 200 bp, and sequencing showed that they were identical with the Cx45 already published. Fluorescence immunohistochemistry showed the existence of immunological signal of Cx45 in most of the detrusor smooth muscles. Conclusion The smooth muscle cells of stable human detrusor are electrically coupled through gap junctions.