Identification of TRPM7 channels in human intestinal interstitial cells of Cajal.
OBJECTIVE
To investigate the characteristics of slow electrical waves and the presence of transient receptor potential melastatin-type 7 (TRPM7) in the human gastrointestinal (GI) tract.


METHODS
Conventional microelectrode techniques were used to record intracellular electrical responses from human GI smooth muscle tissue. Immunohistochemistry was used to identify TRPM7 channels in interstitial cells of Cajal (ICCs).


RESULTS
The human GI tract generated slow electrical waves and had ICCs which functioned as pacemaker cells. Flufenamic acid, a nonselective cation channel blocker, and 2-APB (2-aminoethoxydiphenyl borate) and La(3+), TRPM7 channel blockers, inhibited the slow waves. Also, TRPM7 channels were expressed in ICCs in human tissue.


CONCLUSIONS
These results suggest that the human GI tract generates slow waves and that TRPM7 channels expressed in the ICCs may be involved in the generation of the slow waves.
Kim
Byung Joo
BJ
School of Korean Medicine, Pusan National University, Yangsan 626-870, South Korea.
Park
Kyu Joo
KJ
Kim
Hyung Woo
HW
Choi
Seok
S
Jun
Jae Yeoul
JY
Chang
In Youb
IY
Jeon
Ju-Hong
JH
So
Insuk
I
Kim
Seon Jeong
SJ
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001896:Boron Compounds / Q000494:pharmacology; D005260:Female; D005439:Flufenamic Acid / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000502:physiology; D006801:Humans; D056885:Interstitial Cells of Cajal / Q000166:cytology / Q000378:metabolism*; D007422:Intestines / Q000166:cytology*; D007811:Lanthanum / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D017346:Protein Serine-Threonine Kinases; D050053:TRPM Cation Channels / Q000378:metabolism*
D000893:Anti-Inflammatory Agents; D001896:Boron Compounds; D050053:TRPM Cation Channels; D005439:Flufenamic Acid; D007811:Lanthanum; C109986:2-aminoethoxydiphenyl borate; D017346:Protein Serine-Threonine Kinases; C486583:TRPM7 protein, human