Effects of Ovariectomy and Hormone Replacement on the Rat Lingual Mucosa and Parotid Glands: Histological , Immunohistochemical and Ultrastructural Study

Objective: Although a close relationship between oraldiscomfort and menopause is suggested, it is not clear ifalterations of sex steroids would cause any histological changesin the oral tissues. The aim of this study was to investigatethe possible effects of ovariectomy on rat lingual mucosa andthe parotid glands as well as the effects of hormone replacement.Methods: Thirty adult female albino rats were includedin this study. Ten animals underwent sham operation andconsidered as control group. The remaining twenty animalsunderwent ovariectomy. One month later, ten of the ovariectomizedanimals were given daily oral estrogen and progesteron(hormone replacement therapy group) and other ten animalswere left without treatment (ovariectomized group). Twomonths later, all animals were sacrificed. Tongues weresagitally cut and paraffin sections were prepared. Sectionswere stained with H E and immunohistochemical stainingusing PCNA antibodies. The thickness of the lingual mucosawas measured using the image analyzer at the apex, dorsumand the ventral region. The parotid glands were processed for light and electron microscopy.Results: Ovariectomized animals presented reduced thicknessof the lingual mucosa especially at the tip of the tongue.The lingual papillae were partially disappeared or irregularin appearance. The results of immunohistochemistry showedprolonged turn-over period. The parotid glands demonstratedirregular pattern of the acini. The acini were smaller withhyperchromatic nuclei. There was increased connective tissueand mast cell infiltration. Ultrastructurally, the cells of theacini showed few irregular secretory granules and increasedrough endoplasmic reticulum with vacuolization. Hormonereplacement partially compensated for these changes.Conclusion: The overall results suggested that sex steroidshad a specific role in the maintenance of normal lingualmucosa and parotid glands, and that their deficiency mightlead to the onset of oral discomfort in menopausal womenwhich could be reversed by HRT.