Shandley L, Moritz K M, Samuel C S, Wintour E M
Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Australia.
Reprod Fertil Dev. 1997;9(4):455-64. doi: 10.1071/r96103.
The tensile strength of fetal membranes is largely due to their collagen content. In this study we have examined the changes in collagen in the amniotic and allantoic membranes of the sheep over a wide gestational range (27-142 days of gestation; term, 145-150 days). The results have been correlated with volume changes in normal development, and in particular, the changes in allantois have been studied after a rapid and extensive increase in allantoic volume, as a result of maternal dexamethasone treatment (0.76 mg h-1 for 48 h) from Day 60 of gestation. Electron microscopy and immunohistochemistry were used to delineate collagen distribution, and gel electrophoresis was used to assess the relative proportions of each type. In the amnion, collagen content increased from 37 +/- 4% to 50 +/- 1% dry weight of the tissue from 41-102 days and declined slightly thereafter. In the allantois, collagen content increased from 20 +/- 1% at Day 27 to 50 +/- 6% at Day 142, significantly correlated with a volume increase from 25 +/- 3 mL to 813 +/- 274 mL. Collagen types I (>85%), III (10%) and small amounts of types IV and V (<5%) were identified in both membranes at all ages. When allantoic fluid volume was increased rapidly by maternal dexamethasone infusion, there was a significant decrease in collagen content from 38 +/- 6% to 25 +/- 2% (P < 0.05). By immunohistochemistry it was observed that both epithelial cells and fibroblasts were synthesizing collagen.
胎膜的抗张强度很大程度上归因于其胶原蛋白含量。在本研究中，我们检测了绵羊羊膜和尿囊膜在较广妊娠范围内（妊娠27 - 142天；足月为145 - 150天）胶原蛋白的变化。研究结果与正常发育过程中的体积变化相关，特别是在妊娠60天起经母体地塞米松治疗（0.76 mg/h，持续48小时）导致尿囊体积迅速大幅增加后，对尿囊的变化进行了研究。采用电子显微镜和免疫组织化学方法描绘胶原蛋白分布，并用凝胶电泳评估每种类型的相对比例。在羊膜中，胶原蛋白含量从41 - 102天占组织干重的37±4%增加到50±1%，此后略有下降。在尿囊中，胶原蛋白含量从第27天的20±1%增加到第142天的50±6%，与体积从25±3 mL增加到813±274 mL显著相关。在所有年龄段的两种膜中均鉴定出I型胶原蛋白（>85%）、III型胶原蛋白（10%）以及少量的IV型和V型胶原蛋白（<5%）。当通过母体输注地塞米松使尿囊液体积迅速增加时，胶原蛋白含量从38±6%显著下降至25±2%（P<0.05）。通过免疫组织化学观察到上皮细胞和成纤维细胞均在合成胶原蛋白。
