Two non-vesicular ATP release pathways in the mouse erythrocyte membrane

► ATP release by erythrocytes is attenuated in cells of Pannexin1 deficient mice. ► The Panx1−/− cells reveal a second Panx1 independent pathway for ATP release. ► The alternate pathway is activated by iloprost and inhibited by dipyridamole. ► The alternate release mechanism does not allow for the uptake of extracellular dyes. ► Glibenclamide inhibits Panx1 in the same concentration range as it inhibits CFTR channels.