Published online Mar 7, 2011. doi: 10.3748/wjg.v17.i9.1143
Revised: November 11, 2010
Accepted: November 18, 2010
Published online: March 7, 2011
AIM: To explore the role of prostaglandin F2α (PGF2α)) on pacemaker activity in interstitial cells of Cajal (ICC) from mouse small intestine.
METHODS: In this study, effects of PGF2α in the cultured ICC cells were investigated with patch clamp technology combined with Ca2+ image analysis.
RESULTS: Externally applied PGF2α (10 μmol/L) produced membrane depolarization in current-clamp mode and increased tonic inward pacemaker currents in voltage-clamp mode. The application of flufenamic acid (a non-selective cation channel inhibitor) or niflumic acid (a Cl- channel inhibitor) abolished the generation of pacemaker currents but only flufenamic acid inhibited the PGF2α-induced tonic inward currents. In addition, the tonic inward currents induced by PGF2α were not inhibited by intracellular application of 5’-[-thio]diphosphate trilithium salt. Pretreatment with Ca2+ free solution, U-73122, an active phospholipase C inhibitor, and thapsigargin, a Ca2+-ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker currents and suppressed the PGF2α-induced tonic inward currents. However, chelerythrine or calphostin C, protein kinase C inhibitors, did not block the PGF2α-induced effects on pacemaker currents. When recording intracellular Ca2+ ([Ca2+]i) concentration using fluo-3/AM, PGF2α broadly increased the spontaneous [Ca2+]i oscillations.
CONCLUSION: These results suggest that PGF2α can modulate pacemaker activity of ICC by acting non-selective action channels through phospholipase C-dependent pathway via [Ca2+]i regulation