Fig 7.

The effect of SQ-22536, calphostin C, LY-294002 and AG1478 on the H₂O₂-induced effects on pacemaker currents of ICC and images from the ICC expressing the tyrosine kinase fusion protein, delivered by an adenoviral vector from the murine intestine. (A) The effect of 1 mM H₂O₂ on pacemaker currents after pretreating cells with 10 μM SQ22536, an adenylate cyclase inhibitor, for 10 min. (B) The effect of 1 mM H₂O₂ on pacemaker currents after pretreating cells with 0.1 μM calphostin C, protein kinase C inhibitor, for 10 min. (C) The effect of 1 mM H₂O₂ on pacemaker currents after pretreating cells with 10 μM LY-294002, PI3-kinase inhibitor, for 15 min. (D) In resting cells: a punctuate pattern of fluorescence is observed. (E) When ICC are treated with 1 mM H₂O₂ for 30 min., the ICC becomes diffuse. (F) The effect of 1 mM H₂O₂ on pacemaker currents after pretreating cells with 10 μM AG1478, a potent and selective inhibitor of epidermal growth factor receptor, for 15 min. (G) The effect of 1 μM PGE₂ on pacemaker currents after pretreating cells with 10 μM AG1478. The dotted lines indicate zero current levels.