Role of oxidative stress, angiogenesis and chemo-attractant cytokines in the pathogenesis of ischaemic protection induced by remote ischaemic conditioning: Study of a human model of ischaemia-reperfusion induced vascular injury.

AIMS

We explored the effect of remote ischaemic conditioning (RIC) on endothelial function and on circulating mediators.

METHODS AND RESULTS

In 20 healthy male volunteers (mean age 31 ± 10 years), flow-mediated dilation (FMD) was measured before and after 20 min of arm ischaemia, followed by reperfusion. Remote ischaemic conditioning (RIC) was performed by applying 3 cycles of 5 min of ischaemia of the leg at the onset of index arm ischaemia. Each volunteer underwent the IR-induced vascular injury protocol with and without RIC in a crossover study design. In the control group, IR significantly reduced FMD (5.9 ± 2.9% before IR vs. 2.2 ± 3.7% after IR; p < 0.001). This effect was significantly attenuated by performing RIC (FMD of 5.5 ± 3.1% before IR vs. 4.0 ± 3.4% % after IR; p for interaction = 0.01). Serum levels of SOD and ADMA increased significantly whereas MCP-1 and VEGF levels decreased significantly. Only changes in SOD levels were significantly related to the degree of RIC induced protection (r² = 0.34; p = 0.018).

CONCLUSION

RIC has protective effects against endothelial IR injury. Our biomarker study suggests that anti-oxidative stress mediators, such as SOD, seem to be more involved in the pathogenesis of RIC-induced protection in humans than angiogenesis factors or chemo-attractant cytokines.