The relationship of TRP channels to the pacemaker activity of interstitial cells of Cajal in the gastrointestinal tract.
Interstitial cells of Cajal (ICCs) are a fundamental component of the pacemaker apparatus of the gastrointestinal (GI) tract. They have special properties that make them unique in their ability to generate and propagate slow waves in gastrointestinal smooth muscle. The pacemaker current that generates slow waves is initially due to a voltage-independent, Ca(2+)-inhibited, non-selective cationic conductance in ICC. The classical transient receptor potential (TRPC) channel 4 was suggested as a molecular candidate for the nonselective cation channel (NSCC) responsible for the pacemaker activity. We have shown that TRPC4-/- mice display normal slow waves and suggest that TRPC4 might be an essential component of the NSCC activated by muscarinic stimulation. Finally, we suggest that TRPM7 is the molecular candidate for the NSCC responsible for pacemaker activity in ICCs on the basis of electrophysiological, molecular biological, and immunohistochemical experiments.
Kim
Byung Joo
BJ
Department of Physiology and Biophysics, Seoul National University College of Medicine, Seoul 110-799, Korea. kimbj21c@hanmail.net
So
Insuk
I
Kim
Ki Whan
KW
D000818:Animals; D001683:Biological Clocks / Q000502:physiology; D017615:Enteric Nervous System / Q000166:cytology*; D041981:Gastrointestinal Tract / Q000294:innervation*; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000166:cytology*; D050052:TRPC Cation Channels / Q000502:physiology*
D050052:TRPC Cation Channels