HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 101/3/1151    most recent 90903.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Pezier, A. Articles by Ache, B. W. Search for Related Content PubMed PubMed Citation Articles by Pezier, A. Articles by Ache, B. W.

The Na⁺/Ca²⁺ Exchanger Inhibitor, KB-R7943, Blocks a Nonselective Cation Channel Implicated in Chemosensory Transduction

¹Whitney Laboratory for Marine Bioscience, Center for Smell and Taste, McKnight Brain Institute; and ²Departments of Zoology and Neuroscience, University of Florida, Gainesville, Florida

Submitted 12 August 2008; accepted in final form 22 December 2008

Abstract

The mechanism(s) of olfactory transduction in invertebrates remains to be fully understood. In lobster olfactory receptor neurons (ORNs), a nonselective sodium-gated cation (SGC) channel, a presumptive transient receptor potential (TRP)C channel homolog, plays a crucial role in olfactory transduction, at least in part by amplifying the primary transduction current. To better determine the functional role of the channel, it is important to selectively block the channel independently of other elements of the transduction cascade, causing us to search for specific pharmacological blockers of the SGC channel. Given evidence that the Na⁺/Ca²⁺ exchange inhibitor, KB-R7943, blocks mammalian TRPC channels, we studied this probe as a potential blocker of the lobster SGC channel. KB-R7943 reversibly blocked the SGC current in both inside- and outside-out patch recordings in a dose- and voltage-dependent manner. KB-R7943 decreased the channel open probability without changing single channel amplitude. KB-R7943 also reversibly and in a dose-dependent manner inhibited both the odorant-evoked discharge of lobster ORNs and the odorant-evoked whole cell current. Our findings strongly imply that KB-R7943 potently blocks the lobster SGC channel and likely does so directly and not through its ability to block the Na⁺/Ca²⁺ exchanger.

This article has been cited by other articles:

				G. Wu, X. Xie, Z.-H. Lu, and R. W. Ledeen Sodium-calcium exchanger complexed with GM1 ganglioside in nuclear membrane transfers calcium from nucleoplasm to endoplasmic reticulum PNAS, June 30, 2009; 106(26): 10829 - 10834. [Abstract] [Full Text] [PDF]