TRPC5 as a candidate for the nonselective cation channel activated by muscarinic stimulation in murine stomach.
We investigated which transient receptor potential (TRP) channel is responsible for the nonselective cation channel (NSCC) activated by carbachol (CCh) in murine stomach with RT-PCR and the electrophysiological method. All seven types of TRP mRNA were detected in murine stomach with RT-PCR. When each TRP channel was expressed, the current-voltage relationship of mTRP5 was most similar to that recorded in murine gastric myocytes. mTRP5 showed a conductance order of Cs(+) > K(+) > Na(+), similar to that in the murine stomach. With 0.2 mM GTPgammaS in the pipette solution, the current was activated transiently in both NSCC in the murine stomach and the expressed mTRP5. Both NSCC activated by CCh in murine stomach and mTRP5 were inhibited by intracellularly applied anti-G(q/11) antibody, PLC inhibitor U-73122, IICR inhibitor 2-aminoethoxydiphenylborate, and nonspecific cation channel blockers La(3+) and flufenamate. There were two other unique properties. Both the native NSCC and mTRP5 were activated by 1-oleoyl-2-acetyl-sn-glycerol. Without the activation of NSCC by CCh, the NSCC in murine stomach was constitutively active like mTRP5. From the above results, we suggest that mTRP5 might be a candidate for the NSCC activated by ACh or CCh in murine stomach.
Lee
Young Mee
YM
Department of Physiology and Biophysics, Seoul National University College of Medicine, Seoul 110-799, Korea.
Kim
Byung Joo
BJ
Kim
Hyun Jin
HJ
Yang
Dong Ki
DK
Zhu
Mei Hong
MH
Lee
Kyu Pil
KP
So
Insuk
I
Kim
Ki Whan
KW
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000906:Antibodies / Q000494:pharmacology; D016466:CHO Cells; D002118:Calcium / Q000494:pharmacology; D015220:Calcium Channels / Q000235:genetics* / Q000378:metabolism*; D002217:Carbachol / Q000494:pharmacology*; D027682:Cation Transport Proteins; D002412:Cations / Q000378:metabolism; D006224:Cricetinae; D004075:Diglycerides / Q000494:pharmacology; D005260:Female; D005439:Flufenamic Acid / Q000494:pharmacology; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D005753:Gastric Mucosa / Q000378:metabolism*; D015870:Gene Expression / Q000502:physiology; D020962:Heterotrimeric GTP-Binding Proteins / Q000276:immunology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008813:Mice, Inbred ICR; D018721:Muscarinic Agonists / Q000494:pharmacology*; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000166:cytology; D050052:TRPC Cation Channels
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000906:Antibodies; D015220:Calcium Channels; D027682:Cation Transport Proteins; D002412:Cations; D004075:Diglycerides; D018721:Muscarinic Agonists; D050052:TRPC Cation Channels; C112021:Trpc5 protein, mouse; D005439:Flufenamic Acid; C038237:1-oleoyl-2-acetylglycerol; D002217:Carbachol; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins; D002118:Calcium