著者

松井 等 松井 等 高井 章 柏柳 誠

出版者

PHYSIOLOGICAL SOCIETY OF JAPAN

雑誌

日本生理学会大会発表要旨集

巻号頁・発行日

pp.S123, 2005 (Released:2005-04-16)

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In olfactory receptor cells, it is well established that cAMP acts as a main second messenger during odor responses. Biochemical experiments, however, showed failure of accumulation of cAMP in olfactory cilia by odorants of 40% examined (Sklar et al., 1996). We have shown that application of water soluble odorants and volatile odorants induced inward currents in olfactory cells of the Xenopus water nose but dialysis with cAMP did not (Iida and Kashiwayanagi, 1999). Breer and Boekhoff showed that odorants, which did not induce cAMP accumulation in olfactory cilia, induced IP3 accumulation (1990). Dialysis of olfactory cells in Xenopus water nose with IP3 induced inward currents. In addition, the turtle olfactory cells responded to dialysis with cyclic ADP-ribose (cADPR) with an inward current (Sekimoto and Kashiwayanagi, 2003). The magnitudes of the inward current responses to cAMP-increasing odorants were greatly reduced by prior dialyses of a high concentration of cADPR or 8-Br-cADPR, an antagonist. It is possible that IP3 and cADPR play as second messengers during the olfactory transduction. At present, channel molecules which are activated by these second messenger candidates have not been identified in olfactory cells. Transient receptor potential (TRP) channels, which are expressed in many tissues and cell types in vertebrates, are activated by various stimulations. In the present study, we explore roles of TRP channels in the olfactory system by RT-PCR and immunohistochemical techniques. [Jpn J Physiol 55 Suppl:S123 (2005)]