1. Connexin hemichannels-mediated Ca 2+ entry results in nitric oxide production in in situ injured endothelial cells Everardo Avelino Secondo anno Ciclo XXII

2. Injury provokes a Ca 2+ wave characterized by two phases, peak and plateau PEAK ~ 60% > intracellular stores depletion (P 2 Y 1,2,12,13 ) ~ 40 > Ca2+ influx (P 2 X and Gap junctions) PLATEAU Ca2+ influx (Gap junctions) Introduction

3. Endothelium functions: Angiogenesis and vasculogenesis Preserve a surface unreactive toward circulating cells Mantain thromboresistence Inhibit vascular tone Inhibit cells growth in outer layer of the vesell wall. Introduction

4. Nitric oxide measurement DAF FM DA Fluorescent dye Indicator of NO production Emission: 510nm Excitation: 490nm

5. Injury augments nitric oxide production in rat aortic endothelium

7. Injury induced NOP* depend on extracellular Ca 2+ * Nitric oxide production

8. Capacitative Ca 2+ entry does not sustain injury-induced NOP

9. Putative blockers of CxHcs* reduce NO synthesis induced by Ca 2+ entry in injured endothelium *Connexin hemichannels

10. Putative blockers of CxHcs* reduce NO synthesis induced by Ca 2+ entry in injured endothelium *Connexin hemichannels

11. Connexin mimetic peptides reduce both injury-induced Ca 2+ elevation and NO production in ra aortic EC’s Pre-incubation

12. Connexin mimetic peptides reduce both injury-induced Ca2+ elevation and NO production in ra aortic EC’s Pre-incubation

13. Connexin mimetic peptides reduce both injury-induced Ca2+ elevation and NO production in ra aortic EC’s Accute effect

14. Connexin mimetic peptides reduce both injury-induced Ca2+ elevation and NO production in ra aortic EC’s

15. Summary

16. Nucleus Intracellular Ca2+ stores Ca 2+ ATPase Gap ATP TRPV 4 IP 3 R PG PLC IP3 Ca 2+ eNOS CaM Inhibit CCE Ca 2+ Activates NCCE ? Summary

17. Preeliminar results