Sex Hormone Receptors in Vocal Fold Tissue: A Theory about the Influence of Sex Hormones in the Larynx

OBJECTIVE: The larynx is considered a secondary sexual organ. To demonstrate that sex hormones can directly influence laryngeal function, specific receptors in the vocal cord must be identified. MATERIALS AND METHODS: We searched for estrogen, progesterone and androgen receptors, using an immunohistochemical method, in normal human vocal cords (from 3 cadavers) and in samples of healthy vocal cords and of laryngeal carcinomas from 15 live subjects. Breast and prostate carcinoma were used as controls. RESULTS: In all the normal samples tested, the results were negative; there was only a nonspecific cytoplasmatic response in the subepithelial glands (false positives). In the neoplastic tissue, 2 samples had a weak nuclear focal positivity for estrogen and progesterone receptors; all 15 subjects studied were negative for androgen receptors. CONCLUSIONS: Since our data show that sex hormone receptors are absent in the vocal cords, other theories must be considered to explain the fact that hormones influence the quality of the voice. This study discusses the possibility that the changes of voice according to gender and throughout life might be linked with a different expression of some growth factors in the laryngeal tissue and that this expression might in turn be influenced by hormonal variations