Malm L
Department of Otorhinolaryngology, University of Lund, Sweden.
Acta Otolaryngol. 1987 Sep-Oct;104(3-4):251-4. doi: 10.3109/00016488709107325.
Textbooks of otorhinolaryngology usually report that one-third of women diagnosed for patulous Eustachian tube (tuba aperta) are pregnant or on estrogenic therapy. To investigate whether the opening of the Eustachian tube (ET) can be facilitated experimentally during pregnancy, the ET opening function of 14 pregnant rats was compared with that of 14 nonpregnant controls. The air pressure at which the ET opened (the pressure opening level, Pol) when air is injected into the middle ear, and the pressures maintaining open ET during continued air injection were measured. The Pol was lower in the pregnant rats, whereas there was no difference in pressures between the two groups during open ET. The differences between Pol and the pressures during open ET were smaller in the pregnant rats than in the controls. It was furthermore demonstrated in 2 rats that, after instillation of a surface tension lowering substance in the middle ear, the Pol was reduced markedly, whereas the effect on the pressure during open ET was less pronounced. It is concluded that pregnancy facilitates opening of the ET in rats and it is suggested that it is done by reducing the surface tension of the ET secretion.
耳鼻咽喉科教科书通常报道，被诊断为咽鼓管异常开放的女性中有三分之一处于妊娠状态或正在接受雌激素治疗。为了研究在怀孕期间能否通过实验促进咽鼓管开放，将14只怀孕大鼠的咽鼓管开放功能与14只未怀孕的对照大鼠进行了比较。测量了向中耳注入空气时咽鼓管开放的气压（压力开放水平，Pol），以及持续注入空气期间维持咽鼓管开放的压力。怀孕大鼠的Pol较低，而在咽鼓管开放期间两组之间的压力没有差异。怀孕大鼠的Pol与咽鼓管开放期间的压力之间的差异比对照组小。此外，在2只大鼠中证实，向中耳滴注降低表面张力的物质后，Pol显著降低，而对咽鼓管开放期间压力的影响则不那么明显。得出的结论是，怀孕促进了大鼠咽鼓管的开放，并表明这是通过降低咽鼓管分泌物的表面张力来实现的。
