Praud Christophe, Sebe Philippe, Mondet Fabrice, Sebille Alain
Atelier de régénération neuromusculaire, Faculté de Médecine St Antoine, 27 rue Chaligny, 75571 Paris Cedex 12, France.
Anat Embryol (Berl). 2003 Sep;207(2):169-75. doi: 10.1007/s00429-003-0340-7. Epub 2003 Aug 22.
The aim of this study was to give a microscopic description of the organization, the innervation and the slow or fast type of the striated fibers of the external urethral sphincter in the female rat. Conventional methods for photonic microscopy and immunochemistry were applied to cross and longitudinal sections of snap-frozen urethra. With hematoxylin-eosin stained cross sections, striated fibers are of small diameter and attached directly to the surrounding connective tissue. They are innervated by cholinergic endplates as shown by acetylcholinesterase techniques and alpha-bungarotoxin binding. The histological aspects of the cross sections as well as the distribution of endplates along the length of the sphincter suggest an organization of the fibers in four bundles, possibly acting as a photographic diaphragm does. Like striated skeletal muscle fibers, the fibers bind monoclonal antibodies against dystrophin with subsarcolemmal distribution and against desmin which visualizes striations. All the fibers express fast myosin heavy chains and very few co-express slow myosin heavy chains as determined by immunocytochemistry. We are taking advantage of the diaphragmatic organization of the striated sphincter to develop a longitudinal section as a model of chronic incontinence to test the efficiency of grafted myoblasts provided by fast striated skeletal muscle.
本研究的目的是对雌性大鼠尿道外括约肌横纹肌纤维的组织结构、神经支配以及慢肌或快肌类型进行微观描述。将传统的光子显微镜和免疫化学方法应用于速冻尿道的横切面和纵切面。在苏木精-伊红染色的横切面上，横纹肌纤维直径较小，直接附着于周围的结缔组织。如乙酰胆碱酯酶技术和α-银环蛇毒素结合所示，它们由胆碱能终板支配。横切面的组织学特征以及终板沿括约肌长度的分布表明，纤维呈四束状排列，可能起到类似于摄影光圈的作用。与横纹骨骼肌纤维一样，这些纤维结合抗肌萎缩蛋白的单克隆抗体，其分布于肌膜下，还结合抗结蛋白的单克隆抗体，后者可显示横纹。通过免疫细胞化学测定，所有纤维均表达快肌肌球蛋白重链，很少有纤维共表达慢肌肌球蛋白重链。我们利用横纹括约肌的隔膜组织来制作纵切面，作为慢性尿失禁的模型，以测试由快横纹骨骼肌提供的移植成肌细胞的效率。
