Involvement of Thromboxane A2 in the Modulation of Pacemaker Activity of Interstitial Cells of Cajal of Mouse Intestine

• 영문명: Involvement of Thromboxane A₂ in the Modulation of Pacemaker Activity of Interstitial Cells of Cajal of Mouse Intestine
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Jin Ho Kim Soo Jin Choi Cheol Ho Yeum Pyung Jin Yoon Seok Choi Jae Yeoul Jun
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제12권 제1호, 25~30쪽, 전체 6쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2008.01.01

영문 초록

Although many studies show that thromboxane A₂ (TXA₂) has the action of gastrointestinal (GI) motility using GI muscle cells and tissue, there are no reports on the effects of TXA₂ on interstitial cells of Cajal (ICC) that function as pacemaker cells in GI tract. So, we studied the modulation of pacemaker activities by TXA₂ in ICC with whole cell patch-clamp technique. Externally applied TXA₂ (5ՌM) produced membrane depolarization in current-clamp mode and increased tonic inward pacemaker currents in voltage-clamp mode. The tonic inward currents by TXA₂ were inhibited by intracellular application of GDP-Ղ-S. The pretreatment of ICC with Ca²⁺ free solution and thapsigargin, a Ca²⁺-ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker currents and suppressed the TXA₂-induced tonic inward currents. However, chelerythrine or calphostin C, protein kinase C inhibitors, did not block the TXA₂-induced effects on pacemaker currents. These results suggest that TXA₂ can regulate intestinal motility through the modulation of ICC pacemaker activities. This modulation of pacemaker activities by TXA₂ may occur by the activation of G protein and PKC independent pathway via extra and intracellular Ca²⁺ modulation.

키워드

Thromboxane A₂ (TXA₂) Interstitial cells of Cajal (ICC) Pacemaker currents Intestinal motility