NOS3 and myocardial ischemia: The main findings of the present study are: (1) circulating NOS3 reduces infarct size in a myocardial ischemia/reperfusion model of chimeric mice; (2) this translates into a sustained reduction of LV function; (3) depletion of circulating NOS3 reduces circulating NO pool by 1/3, as evidenced by reduced plasma levels of nitrite; (4) circulating NOS3 limits RBC deformability.