The Role of TREK-1 and AQP5 in Gonadocorticoid-Related Voice Disorders.

Objectives: TWIK-related potassium channel-1 (TREK-1) and Aquaporin 5 (AQP5) are involved in epithelial integrity and fluid transport, respectively. In this study, we aimed to compare physiological and gestational patterns of TREK-1 and AQP5 location and expression in rat larynx. Our secondary objective was to reveal the effect of estradiol (E2) and progesterone (PG) on these two biomolecules.

Methods: This study was conducted on 20 Wister albino female rats which were assigned as control (group A) and pregnant group (group B). The rats were sacrificed at 20th day of pregnancy. Blood was obtained directly from the ventricle for detection of serum E2 and PG levels. Larynx was resected for immunohistochemical analyses and real-time polymerase chain reaction testing for detection of TREK-1 and AQP5 staining and expression, respectively.

Results: Relative TREK-1 (P = 0.035) and AQP5 (P = 0.019) expression was found to be significantly high in group B when compared with group A. We found positive correlation between serum E2 levels and both biomolecules (TREK-1; P = 0.018, AQP5; P = 0.016). We also found positive correlation between serum PG levels and both biomolecules (TREK-1; P = 0.001, AQP5; P = 0.019). TREK-1 immunostaining was found to be higher in surface epithelium and lamina propria of vocal cord mucosa. AQP5 was particularly found to be located in basement membrane and adjacent superficial lamina propria. We revealed the physiological and gestational pattern of laryngeal TREK-1 and AQP5 expression for the first time. Gestational expression of both TREK-1 and AQP5 was found to be increased. Stimulatory effect of E2 and PG on laryngeal TREK-1 and AQP5 expression was also revealed.

Conclusions: We revealed upregulatory effect of E2 and PG on laryngeal TREK-1 and AQP5 expression. Based on this finding, it can be suggested that TREK-1 and AQP5 play role in biomolecular processes leading gonadocorticoid-related voice changes.