Repetition of Ischemic Preconditioning Augments Endothelium-Dependent Vasodilation in Humans

Abstract

Background-Several studies have shown that both early and late effects of ischemic preconditioning (IPC) protect against myocardial injury after ischemic reperfusion. Methods and Results-The purpose of this study was to evaluate the late effects of IPC on endothelial function in humans.Late phase of IPC was induced by upper limb ischemia (cuff inflation of over 200 mm Hg for 5 minutes) 6 times a day for 1 month. We evaluated forearm blood flow (FBF) responses to acetylcholine (ACh) and to sodium nitroprusside (SNP) before and after IPC stimulus in 30 young healthy men. FBF was measured using a strain-gauge plethysmograph. The IPC stimulus significantly increased plasma concentration of vascular endothelial growth factor (VEGF), circulating level of endothelial progenitor cells (EPCs), and FBF responses to ACh, but these did not change in the control group. The FBF responses to SNP were similar before and after the IPC stimulus. Infusion of N G -monomethyl-L-arginine, a nitric oxide synthase inhibitor, completely eliminated the IPC stimulus-induced augmentation of FBF responses to ACh. In the cotralateral arms of subjects that received the IPC stimulus, FBF responses to ACh did not change, but levels of VEGF and circulating EPCs increased. Conclusions-These findings suggest that repetition of late IPC stimulus augments endothelium-dependent vasodilation in humans through increases in nitric oxide production and number of EPCs under a local condition. Repetition of IPC stimulus may be a simple, safe, and feasible therapeutic technique for endothelial protection of peripheral vessels.

Ischaemic preconditioning does not alter the determinants of endurance running performance in the heat

“…This may occur reduced mitochondrial oxygen consumption (Cooper & Brown 2008), although a reduced oxygen consumption for a given submaximal exercise intensity is not uniformly observed (De Groot et al 2010). There is also likely an effect of IP in promoting endothelial nitric oxide biosynthesis (Kimura et al 2007), which appears to maintain vascular function that may be impaired following high intensity exercise (Bailey, Birk, et al 2012). In turn, such changes will serve to maintain the supply of oxygen and energy substrates, whilst removing metabolites during exercise.…”

Impact of eight weeks of repeated ischaemic preconditioning on brachial artery and cutaneous microcirculatory function in healthy males

“…1,2 Recent studies have examined daily exposure of IPC episodes as a therapeutic intervention and found enhanced brachial artery endothelial function 3 , skin perfusion 3 , resistance 4 artery function and protection from conduit artery induced IRI 5 . Therefore, daily IPC may potentially be a useful intervention to improve vascular function.…”

Delayed preconditioning prevents ischemia/reperfusion-induced endothelial injury in rats: role of ROS and eNOS

“…11 This study focuses on the late phase of IPC, termed delayed preconditioning, because delayed IPC confers a longer window of cytoprotection and has greater significance for cardiovascular protection. 12 The molecular mechanisms and mediators that account for delayed IPC have been extensively investigated, and it has emerged that eNOS has a key role in this phenomenon in the heart. 9,13 In addition, IPC was reported to reduce the generation of cardiac ROS/RNS after both the acute and late phase of postischemic reperfusion.…”