Droegemueller W, Chvapil M, Vining J, Whitaker L, Christian C D
Am J Obstet Gynecol. 1978 Dec 1;132(7):775-82. doi: 10.1016/s0002-9378(78)80012-x.
The minimal elasticity of the uterine cervix has been related to its high collagen content. By interfering with cohesive forces that hold the collagen fiber bundle together, it is possible to diminish the physical strength of collagen. Urea has been used in collagen chemistry to dissociate collagen by interfering with hydrophobic linkages and hydrogen bonds. This results in a change of mechanical properties such as a decrease in tensile strength and an increase in elasticity. Basic studies of rat tail tendon demonstrated the additive effects of pH, concentration of urea, and temperature on the mechanical characteristics of collagen fibers. In vitro testing was performed using an injection of 30 per cent urea at pH 4. Serial measurements with a spring gauge instrument showed a reduction in cervical resistance. A cervical injection technique has been developed and toxicity of urea studied.
子宫颈的最小弹性与其高胶原蛋白含量有关。通过干扰将胶原纤维束维系在一起的内聚力，可以降低胶原蛋白的物理强度。尿素已被用于胶原蛋白化学中，通过干扰疏水键和氢键来使胶原蛋白解离。这会导致机械性能的改变，如拉伸强度降低和弹性增加。对大鼠尾腱的基础研究表明，pH值、尿素浓度和温度对胶原纤维的机械特性具有累加效应。在体外试验中，采用在pH值为4时注射30%尿素的方法。使用弹簧测量仪进行系列测量显示宫颈阻力降低。已经开发出一种宫颈注射技术，并对尿素的毒性进行了研究。
