Improved endothelial-dependent and endothelial-independent skin vasodilator responses following remote ischemic preconditioning.
Am J Physiol Heart Circ Physiol. 2019 Nov 27;:
Authors: Kim J, Franke WD, Lang JA
INTRODUCTION: One week of daily remote ischemic preconditioning (RIPC) improves cutaneous vasodilatory (VD) function. However, the underlying mechanisms and the number of sessions needed to optimize this adaptive response remain unclear. We hypothesized that the responses to localized heating of the skin will be greater after 2 weeks as opposed to 1 week of RIPC. Furthermore, 2 weeks of repeated RIPC will augment cutaneous VD responses to thermal and pharmacological stimuli.
METHODS: Twenty-four participants (24±2 years; 13 males, 11 females) performed repeated RIPC (7 daily sessions over 1 week, n=11; 12 sessions over 2 weeks, n=13) consisting of 4 repetitions of 5 min of arm blood flow occlusion separated by 5 min reperfusion. Laser speckle contrast imaging was used to measure skin blood flow responses, as perfusion units (PU), to local heating (Tloc=42 oC), acetylcholine (ACh), and sodium nitroprusside (SNP) before and after repeated RIPC. Data were expressed as cutaneous vascular conductance (CVC=PU∙mmHg-1).
RESULTS: The VD response to local heating increased after RIPC (∆CVC from baseline; 1 week: 0.94 ± 0.11 to 1.19 ± 0.15, 2 week: 1.18 ± 0.07 to 1.33 ± 0.10 PU∙mmHg-1; p<0.05) but the ∆CVC did not differ between weeks. SNP-induced VD increased after 2 weeks of RIPC (∆CVC; 0.34 ± 0.07 to 0.63 ± 0.11 PU∙mmHg-1; p<0.05) but ACh-induced VD did not.
CONCLUSION: Repeated RIPC improves local heating- and SNP-mediated cutaneous VD. Compared to 1 week of RIPC, 2 weeks of RIPC does not induce further improvements in cutaneous VD function.
PMID: 31774694 [PubMed – as supplied by publisher]