The orientation and function of smooth muscle in the cervix may contribute to the important biomechanical properties that change during pregnancy. Thus, this study examined the three-dimensional structure, smooth muscle phenotype, and mechanical and contractile functions of the upper and lower cervix of nongravid (not pregnant) and gravid (pregnant) mice. In gravid cervix, we uncovered region-specific changes in the structure and organization of fiber tracts. We also detected a greater proportion of contractile smooth muscle cells (SMCs), but an equal proportion of synthetic SMCs, in the upper versus lower cervix. Furthermore, we revealed that the lower cervix had infrequent spontaneous contractions, distension had a minimal effect on contractility, and the upper cervix had forceful contractions in response to labor-inducing agents (oxytocin and prostaglandin E 2 ). These findings identify regional differences in cervix contractility related to contractile SMC content and fiber organization, which could be targeted with diagnostic technologies and for therapeutic intervention.

中文翻译：

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妊娠小鼠子宫颈三维纤维组织、平滑肌细胞表型和收缩力的区域差异


宫颈平滑肌的方向和功能可能有助于怀孕期间发生变化的重要生物力学特性。因此，本研究检查了非妊娠 （未怀孕） 和妊娠 （怀孕） 小鼠上下宫颈的三维结构、平滑肌表型以及机械和收缩功能。在妊娠宫颈中，我们发现了纤维束结构和组织的区域特异性变化。我们还在上宫颈与下宫颈中检测到更大比例的收缩平滑肌细胞 （SMC），但合成 SMC 的比例相等。此外，我们发现下宫颈不经常自发收缩，膨胀对收缩力的影响最小，并且上宫颈对引产剂 （催产素和前列腺素 E 2） 有力收缩。这些发现确定了与收缩 SMC 内容和纤维组织相关的宫颈收缩力的区域差异，这可以通过诊断技术和治疗干预来靶向。