Estrogen Receptor in the Larynx of the Aged Baboon (Papio Cynocephalus)

Using autoradiographic techniques, tritiated estrogen-receptor complex intranuclear labeling was identified in certain laryngeal tissues of four aged female baboons; no complex labeling was found in the control animal. Three significant findings were felt to be derived from this study. One, surface epithelium of the larynx had essentially no estrogen-receptor activity. Two, all tissues of mesenchymal origin, especially lamina propria, muscle, dense connective tissue, and fat had consistently high levels of nuclear localization of the labeled estrogen. The binding affinity seemed to be the highest at the anterior commissure and the immediate anterior subglottic space. Three, there was a high level of receptor binding in laryngeal cartilage and perichondrium. Since the activated hormone-receptor complex modulates gene expression to alter the amount of mRNA, sex steroids have a direct regulatory effect upon the target cell and, perhaps through an induction process, can exert an indirect effect upon adjacent tissues. It is postulated that since the larynx is a sexually dimorphic organ, the sex steroids and their receptors may play a role in altered phonation during aging and possibly in the development of laryngeal neoplasms and other diseases. Therefore, hormonal manipulation may play a future role in the therapy of laryngeal diseases. This study represents the first demonstration of estrogen receptors by specific anatomic location in the primate larynx with significant localization in the mesenchymal tissues but not in the epithelial tissues.