晚孕期肛提肌Ⅰ、Ⅲ型胶原和基质金属蛋白酶-1表达研究

Expressions of collagen type Ⅰ and Ⅲ,and MMP-1 in levator ani muscle of pregnant women in the third trimester

目的探讨妊娠晚期妇女和未育妇女肛提肌Ⅰ、Ⅲ型胶原和基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)mRNA的表达水平及两者之间的相关性。方法选取20例妊娠晚期孕妇[年龄(28±4)岁,孕龄(39±3)周]为晚期妊娠组。同时,选取因会阴裂伤留取肛提肌组织标本的5例会阴裂伤的已婚未育妇女[年龄(25±4)岁]为对照组。采用HE染色观察肛提肌形态,免疫组织化学和半定量逆转录PCR(reverse transcription PCR,RT-PCR)法检测标本中Ⅰ、Ⅲ型胶原和MMP-1 mRNA表达水平。结果晚期妊娠组肛提肌组织肌纤维肥大,排列紧密但略微紊乱,无变性坏死表现。晚期妊娠组Ⅰ、Ⅲ型胶原蛋白表达及二者比例均显著高于对照组(P<0.05);而MMP-1 mRNA表达水平显著低于对照组(P<0.05)。结论妊娠晚期妇女肛提肌胶原合成增加,降解降低,出现肌纤维肥大,支持力量增加。

Objective To investigate the changes of the expressions of collagens type Ⅰ , type Ⅲ, and MMP-1 in the levator ani muscle of pregnant women. Methods Twenty women after vaginal delivery [ age mean （ 28 ± 4） years, duration of pregnancy mean （39 ± 3 ） weeks ] were the late pregnant group and 5 women with perineal laceration but without delivery [ age mean （25 ± 4 ） years ] served as the control group. All of them accepted our informed consent. Their levator ani muscle tissue samples were extracted. Semi-quantitative reverse transcription polymerase chain reaction （RT-PCR）, haematoxylin-eosin （HE） staining and immunohistochemistry were performed to detect the expressions of collagens type Ⅰ, type Ⅲ, and MMP-1. Results The muscle fiber of levator ani from the late pregnant group was more hypertrophy than that of the control group, in an close but bit of disordered arrange without necrotic appearance. The late pregnant group showed increased positive staining of collagen types Ⅰ and m and elevated ratio of type Ⅰ / Ⅲ （P 〈 0. 05 ）. The optical density （OD） values of MMP-1 mRNA in the late pregnant group was lower than control group （ P 〈 0. 05 ）. Conclusion Muscle fiber of levator ani from the late pregnant group is more hypertrophy than that of the control group, and accommodation of collagen is increased relatively.