@article {Tillinge7, author = {L M Tilling and J M Hunt and A Donald and B Clapp and P J Chowienczyk}, title = {YIA 6 Effects of limb ischaemia-reperfusion and radial artery injury on endothelial function and circulating CD133+/CD34+/VEGFR2+ endothelial progenitor cells}, volume = {97}, number = {20}, pages = {e7--e7}, year = {2011}, doi = {10.1136/heartjnl-2011-300920a.6}, publisher = {BMJ Publishing Group Ltd}, abstract = {Rationale Circulating endothelial progenitor cells (EPC) increase after cardiovascular (CV) events. Whether this results from ischaemia or endothelial injury is unknown. We investigated effects of limb ischaemia-reperfusion (IR) and endothelial injury (EI) on endothelial function and EPC.Methodology Healthy subjects (n=42, 18{\textendash}35 yr) underwent either limb IR generated by cuff inflation, or EI, induced by wire rotation through a cannula. Endothelial function was assessed by flow mediated dilation (FMD) and circulating CD34+/CD133+/VEGFR2+ EPC were enumerated by flow cytometry at baseline, 10 min, 1 h, 6 h, 2 days and 7 days. FMD and cytometry were also performed in patients (n=23, 40{\textendash}75 yr) after EI from radial sheath insertion for coronary angiography, at baseline, 2 days, 7 days, 1 month and 4 months.Results Endothelial dysfunction occurred immediately after IR (50\% reduction from baseline at 10 min, p\<0.001), recovering to baseline after 6 h. After EI FMD fell by 80\% (p\<0.001), recovering by 2 days. In patients, a sustained fall in FMD after EI remained significant at 1 month. After IR CD133+/CD34+ cells increased after 7 days compared to 1 h (82.1{\textpm}13/100 000 vs 62.2{\textpm}8.8/100 000 cells, p\<0.05). After EI CD133+/CD34+ cells increased after 7 days compared to baseline (105.3{\textpm}15.8/100 000 vs 77.9{\textpm}10.3/100 000 cells, p\<0.05). In patients CD133+/VEGFR2+ cells fell at 2 days (by 27.6{\textpm}11.8/100 000 cells, p\<0.05) compared with baseline. There was no significant change in CD133+/CD34+ cells.Conclusions IR and EI cause significant endothelial dysfunction, proportional to the insult. More severe EI reduces CD133+/VEGFR2+ cells, consistent with consumption during repair. In health, CD133+/CD34+ cells expand after arterial insult. No expansion occurs in patients with CV risk factors, possibly reflecting impaired EPC mobilisation.}, issn = {1355-6037}, URL = {https://heart.bmj.com/content/97/20/e7.56}, eprint = {https://heart.bmj.com/content/97/20/e7.56.full.pdf}, journal = {Heart} }