UC Irvine

The effects of exogenous ATP on Ca2+ signaling and wound healing were investigated in rat gastric microvascular endothelial cells (RGMEC). ATP (10 microM) triggered a significant rise in intracellular Ca2+ concentration ([Ca2+]i) from 46+/-2 nM at baseline to peak values averaging 283+/-31 nM (n = 5 experiments, 132 cells). Return to the basal [Ca2+]i was delayed by slowly declining plateau phase that persisted for 200+/-30 s. Removal of extracellular Ca2+ did not significantly affect the peak rise in [Ca2+]i, but reduced the plateau. ATP (10 microM) also significantly increased the migration of RGMEC in a wounded monolayer. Addition of the non-subtype selective purinergic receptor antagonist, suramin, abrogated the effects of ATP on [Ca2+]i and migration. We conclude that local elevation of ATP acting through purinergic receptors induce Ca2+ signals in RGMEC and may contribute to endothelial cell migration.