Malm L
Department of Oto-Rhino-Laryngology, University Hospital, Lund, Sweden.
Acta Otolaryngol Suppl. 1989;457:154-8. doi: 10.3109/00016488809138900.
Patulous Eustachian tube (tuba aperta) is a distressing condition for the patient with such symptoms as autophony and a sensation of fullness in the ear. One-third of women with the diagnosis are pregnant or taking oestrogens. To study whether opening of the Eustachian tube is facilitated during pregnancy, the tube opening function of 14 pregnant rats was compared with that of 14 non-pregnant controls. The middle ear air pressure at which the tube opened (the pressure opening level, Pol) was lower in pregnant rats than in controls; and the difference between Pol and the pressure during open tube (at continued air injection) was less in the pregnant rats. In two additional rats it was then demonstrated that instillation of a surface tension lowering substance in the middle ear caused similar pressure changes as occur during pregnancy. It is concluded that opening of the Eustachian tube in rats is facilitated in pregnancy, and it is suggested that this is due to a reduction in surface tension of the Eustachian tube secretion.
咽鼓管异常开放对患者来说是一种令人苦恼的状况，会出现自听增强和耳部胀满感等症状。确诊为此病的女性中有三分之一处于孕期或正在服用雌激素。为研究孕期咽鼓管开放是否更容易，将14只怀孕大鼠的咽鼓管开放功能与14只非怀孕对照大鼠进行了比较。怀孕大鼠咽鼓管开放时的中耳气压（压力开放水平，Pol）低于对照组；并且怀孕大鼠中Pol与开放管时（持续注入空气）的压力之间的差异更小。随后在另外两只大鼠中证明，向中耳滴注降低表面张力的物质会引起与孕期相似的压力变化。得出的结论是，怀孕时大鼠的咽鼓管更容易开放，并且推测这是由于咽鼓管分泌物表面张力降低所致。
