SPLTRAK Abstract Submission
Modulatory Effect of Arginyl Dipeptides on the Frequency of NaCl Elicited Responses in Cultured Human Fungiform Taste Papillae (HBO) Cells
Jiao-Jiao Xu1, Andrew I. Spielman2, Hau Y. Chung3, M. Hakan Ozdener1
1Monell Chemical Senses Center, Philadelphia, PA, United States
2College of Dentistry, New York University, New York, NY, United States
3The Chinese University of Hong Kong, Hong Kong, Hong Kong

Salty taste is one of the five basic tastes and is often elicited by NaCl. Because excess sodium intake is associated with many health problems. Identifying salt taste modulators will provide a potent boost to salty taste which may result in having safe and well-liked sodium chloride enhancers that improve human health.  In this study, we investigated the role of arginyl dipeptides on NaCl-induced responses in cultured human fungiform taste papillae (HBO) cells. We examined five arginyl dipeptides and two non-arginyl dipeptides. Found only Ala-Arg (AR), Arg-Ala (RA), Arg-Pro (RP) dipeptides significantly increased the number of cell responses to NaCl, whereas no effect was observed with others. Pharmacological studies showed that AR significantly increased responses of amiloride-sensitive but not amiloride-insensitive cells. In studies using small interfering RNAs (siRNAs), responses to AR were significantly decreased in cells transfected with siRNAs against epithelial sodium channel ENaCα or ENaCδ compared to untransfected cells. Altogether, AR increased responses of amiloride-sensitive cells required ENaCα and ENaCδ.