Fig. 5.

Plasma nitrite generated by RIC attenuates cell death in a model of hypoxia-reoxygenation. Cells were exposed to 5 h of anoxia (1% O₂, 2.5 mmol/L 2-deoxyglucose, pH 6.5) to mimic ischemia, followed by reperfusion (1 h) and then cell death was measured by lactate dehydrogenase release. Panels A and B show percentage of survival in normoxic cells, those exposed to hypoxia-reoxygenation (HR) alone, or in the presence of 100 µl of plasma from subjects at baseline (BL) or after each cycle of RIC (C1-C4) or 24 h later (24 H) in the (A) arm or (B) thigh. In a second group of experiments, the plasma was first treated with acidified sulfanilamide (plasma+AS) to decrease nitrite concentration before being used to treat the cells (gray bars). All data are means±SEM. *p<0.01 compared to HR alone. §p<0.01 for plasma versus plasma+AS. N=10.