(-)-epigallocatechin gallate inhibits the pacemaker activity of interstitial cells of cajal of mouse small intestine.
The effects of (-)-epigallocatechin gallate (EGCG) on pacemaker activities of cultured interstitial cells of Cajal (ICC) from murine small intestine were investigated using whole-cell patch-clamp technique at 30 and Ca(2+) image analysis. ICC generated spontaneous pacemaker currents at a holding potential of -70 mV. The treatment of ICC with EGCG resulted in a dose-dependent decrease in the frequency and amplitude of pacemaker currents. SQ-22536, an adenylate cyclase inhibitor, and ODQ, a guanylate cyclase inhibitor, did not inhibit the effects of EGCG. EGCG-induced effects on pacemaker currents were not inhibited by glibenclamide, an ATP-sensitive K(+) channel blocker and TEA, a Ca(2+)-activated K(+) channel blocker. Also, we found that EGCG inhibited the spontaneous [Ca(2+)](i) oscillations in cultured ICC. In conclusion, EGCG inhibited the pacemaker activity of ICC and reduced [Ca(2+)](i) oscillations by cAMP-, cGMP-, ATP-sensitive K+ channel-independent manner.
Department of Rehabilitation, College of Medicine, Chosun University, Gwangju 501-759, Korea.
Kweon Young
KY
Kim
Soo Jin
SJ
Choi
Hyuk Jin
HJ
Jang
Dong Chuan
DC
Zuo
Pawan Kumar
PK
Shahi
Shankar Prasad
SP
Parajuli
Cheol Ho
CH
Yeum
Pyung Jin
PJ
Yoon
Seok
S
Choi
Jae Yeoul
JY
Jun