Biaxial Murine Vaginal Remodeling With Reproductive Aging.
Biaxial Murine Vaginal Remodeling With Reproductive Aging.
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伴随生殖衰老的双轴小鼠阴道重塑。
DOI：
10.1115/1.4054362
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Miller,KristinS
中科院分区：
文献类型：
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作者：
White,ShelbyE;Kiley,JasmineX;Visniauskas,Bruna;Lindsey,SarahH;Miller,KristinS
较高的生育年龄与妊娠期糖尿病、先兆子痫和分娩期间严重阴道撕裂的风险增加相关。此外，更年期与阴道僵硬有关。然而，绝经前生殖衰老过程中阴道的机械特性尚不清楚。因此，本研究的第一个目标是量化未产小鼠阴道随生殖衰老的双轴机械特性。更年期还与弹性纤维含量的减少有关，这可能导致阴道变硬。因此，我们的第二个目标是确定弹性纤维破坏对双轴阴道机械性能的影响。为了实现这一目标，对 2-14 个月龄 CD-1 小鼠的阴道样本进行了延伸充气测试方案（总共 n = 64；n = 16/年龄组）。然后，随机分配一半样品通过弹性蛋白酶消化进行弹性纤维断裂（总共 n = 32；8/年龄组）以评估弹性纤维的作用。在对照和弹性蛋白酶处理的阴道内，材料硬度随着生育年龄而在圆周和轴向方向上增加。阴道表现出各向异性的机械行为，并且各向异性随着年龄的增长而增加。总之，随着生育年龄的阴道重塑包括方向依赖性材料刚度的增加，弹性纤维破坏后材料刚度进一步增加。需要进一步的工作来量化怀孕期间和产后随着生殖年龄的阴道重塑，以更好地了解与年龄相关的阴道重塑如何导致阴道撕裂的风险增加。
Higher reproductive age is associated with an increased risk of gestational diabetes, pre-eclampsia, and severe vaginal tearing during delivery. Further, menopause is associated with vaginal stiffening. However, the mechanical properties of the vagina during reproductive aging before the onset of menopause are unknown. Therefore, the first objective of this study was to quantify the biaxial mechanical properties of the nulliparous murine vagina with reproductive aging. Menopause is further associated with a decrease in elastic fiber content, which may contribute to vaginal stiffening. Hence, our second objective was to determine the effect of elastic fiber disruption on the biaxial vaginal mechanical properties. To accomplish this, vaginal samples from CD-1 mice aged 2–14 months underwent extension-inflation testing protocols (n = 64 total; n = 16/age group). Then, half of the samples were randomly allocated to undergo elastic fiber fragmentation via elastase digestion (n = 32 total; 8/age group) to evaluate the role of elastic fibers. The material stiffness increased with reproductive age in both the circumferential and axial directions within the control and elastase-treated vaginas. The vagina demonstrated anisotropic mechanical behavior, and anisotropy increased with age. In summary, vaginal remodeling with reproductive age included increased direction-dependent material stiffness, which further increased following elastic fiber disruption. Further work is needed to quantify vaginal remodeling during pregnancy and postpartum with reproductive aging to better understand how age-related vaginal remodeling may contribute to an increased risk of vaginal tearing.