| First Author | Leal Denis MF | Year | 2013 |
| Journal | Biochim Biophys Acta | Volume | 1830 |
| Issue | 10 | Pages | 4692-707 |
| PubMed ID | 23742824 | Mgi Jnum | J:202537 |
| Mgi Id | MGI:5519994 | Doi | 10.1016/j.bbagen.2013.05.033 |
| Citation | Leal Denis MF, et al. (2013) Kinetics of extracellular ATP in mastoparan 7-activated human erythrocytes. Biochim Biophys Acta 1830(10):4692-707 |
| abstractText | BACKGROUND: The peptide mastoparan 7 (MST7) stimulated ATP release in human erythrocytes. We explored intra- and extracellular processes governing the time-dependent accumulation of extracellular ATP (i.e., ATPe kinetics). METHODS: Human erythrocytes were treated with MST7 in the presence or absence of two blockers of pannexin 1. ATPe concentration was monitored by luciferin-luciferase based real-time luminometry. RESULTS: Exposure of human erythrocytes to MST7 led to an acute increase in [ATPe], followed by a slower increase phase. ATPe kinetics reflected a strong activation of ATP efflux and a low rate of ATPe hydrolysis by ectoATPase activity. Enhancement of [ATPe] by MST7 required adhesion of erythrocytes to poly-D-lysin-coated coverslips, and correlated with a 31% increase of cAMP and 10% cell swelling. However, when MST7 was dissolved in a hyperosmotic medium to block cell swelling, ATPe accumulation was inhibited by 49%. Erythrocytes pre-exposure to 10muM of either carbenoxolone or probenecid, two blockers of pannexin 1, exhibited a partial reduction of ATP efflux. Erythrocytes from pannexin 1 knockout mice exhibited similar ATPe kinetics as those of wild type mice erythrocytes exposed to pannexin 1 blockers. CONCLUSIONS: MST7 induced release of ATP required either cell adhesion or strong activation of cAMP synthesis. Part of this release required cell swelling. Kinetic analysis and a data driven model suggested that ATP efflux is mediated by two ATP conduits displaying different kinetics, with one conduit being fully blocked by pannexin 1 blockers. GENERAL SIGNIFICANCE: Kinetic analysis of extracellular ATP accumulation from human erythrocytes and potential effects on microcirculation. |
