Ho Kossen M, Borja Mario Cortina, Persson Katarina, Brading Alison F, Andersson Karl-Erik
Oxford Continence Group, University Department of Pharmacology, University of Oxford, Oxford, United Kingdom.
J Urol. 2003 Jun;169(6):2407-11. doi: 10.1097/01.ju.0000055607.67581.09.
While we have recently detected neuronal nitric oxide synthase (nNOS) immunoreactivity in a heterogeneous population of human male urethral striated muscle, to our knowledge the association of nNOS in the female counterpart is unknown. We investigated the association of nNOS with female urethral striated muscle and re-investigated muscle fiber types.
Cryostat sections were taken from the middle third of 4 human female urethras. Nicotinamide adenine dinucleotide phosphate diaphorase histochemistry and nNOS immunohistochemistry were performed. Muscle fiber types were identified by myofibrillar adenosine triphosphatase histochemistry and fast twitch troponin T immunohistochemistry. The association between nNOS immunoreactivity and muscle fiber type was analyzed.
Positive staining for nicotinamide adenine dinucleotide phosphate diaphorase histochemistry and nNOS immunoreactivity were recognized in the sarcolemma of 43.9% of female urethral striated muscle fibers. Immunoreactivity for fast twitch troponin T immunohistochemistry was demonstrated by 2% of the striated fibers. The use of myofibrillar adenosine triphosphatase showed that all fibers darkly stained uniformly at a pH of 9.6, 4.6 and 4.3, suggesting that they were myofibrillar intermediate muscle fibers. The results allowed the differentiation of 2 subgroups of fibers, namely smaller fibers (modal diameter 10.1 to 15.0 microm.) without nNOS immunoreactivity and larger fibers (modal diameter 15.1 to 20.0 microm.) with nNOS immunoreactivity.
To our knowledge female urethral striated muscle has for the first time been found to consist of myofibrillar intermediate fibers and nNOS was positively localized in the sarcolemma of a subgroup of the fibers. This study provides a basis for further investigation into female urethral striated sphincter function and changes in pathological conditions.
虽然我们最近在人类男性尿道横纹肌的异质群体中检测到神经元型一氧化氮合酶（nNOS）免疫反应性，但据我们所知，nNOS在女性对应组织中的关联尚不清楚。我们研究了nNOS与女性尿道横纹肌的关联，并重新研究了肌纤维类型。
从4名女性尿道的中三分之一处取冰冻切片。进行烟酰胺腺嘌呤二核苷酸磷酸黄递酶组织化学和nNOS免疫组织化学检测。通过肌原纤维三磷酸腺苷酶组织化学和快肌肌钙蛋白T免疫组织化学鉴定肌纤维类型。分析nNOS免疫反应性与肌纤维类型之间的关联。
43.9%的女性尿道横纹肌纤维的肌膜中烟酰胺腺嘌呤二核苷酸磷酸黄递酶组织化学染色呈阳性，nNOS免疫反应性也被识别。2%的横纹肌纤维快肌肌钙蛋白T免疫组织化学呈免疫反应性。肌原纤维三磷酸腺苷酶的检测显示，所有纤维在pH值为9.6、4.6和4.3时均均匀深染，表明它们是肌原纤维中间肌纤维。结果可区分出2个纤维亚组，即无nNOS免疫反应性的较小纤维（模态直径10.1至15.0微米）和有nNOS免疫反应性的较大纤维（模态直径15.1至20.0微米）。
据我们所知，首次发现女性尿道横纹肌由肌原纤维中间纤维组成，nNOS阳性定位于一部分纤维的肌膜中。本研究为进一步研究女性尿道横纹括约肌功能及病理状态下的变化提供了基础。
