Remote ischemic preconditioning triggers changes in autonomic nervous system activity: implications for cardioprotection
Date
2017-02-05
Authors
Abdul-Ghani, Safa
Fleishman, Arnold N.
Khaliulin, Igor
Meloni, Marco
Angelini, Gianni D.
Suleiman, M-Saadeh
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley-Blackwell on behalf of The Physiological Society and the American Physiological Society
Abstract
Cardioprotective efficacy of remote ischemic preconditioning (RIPC) remains
controversial. Experimental studies investigating RIPC have largely monitored
cardiovascular changes during index ischemia and reperfusion with little work
investigating changes during RIPC application. This work aims to identify cardiovascular
changes associated with autonomic nervous system (ANS) activity
during RIPC and prior to index ischemia. RIPC was induced in anesthetized
male C57/Bl6 mice by four cycles of 5 min of hindlimb ischemia using
inflated cuff (200 mmHg) followed by 5 min reperfusion. Electrocardiography
(ECG) and microcirculatory blood flow in both hindlimbs were recorded
throughout RIPC protocol. Heart rate variability (HRV) analysis was performed
using ECG data. Hearts extracted at the end of RIPC protocol were
used either for measurement of myocardial metabolites using high-performance
liquid chromatography or for Langendorff perfusion to monitor function
and injury during 30 min index ischemia and 2 h reperfusion. Isolatedperfused
hearts from RIPC animals had significantly less infarct size after
index ischemia and reperfusion (34 5% vs. 59 7%; mean SE
P < 0.05). RIPC protocol was associated with increased heart rate measured
both in ex vivo and in vivo. Frequency ratio of HRV spectra was altered in
RIPC compared to control. RIPC was associated with a standard hyperemic
response in the cuffed-limb but there was a sustained reduction in blood flow
in the uncuffed contralateral limb. RIPC hearts (prior to index ischemia) had
significantly lower phosphorylation potential and energy charge compared to
the control group. In conclusion, RIPC is associated with changes in ANS
activity (heart rate, blood flow, HRV) and mild myocardial ischemic stress
that would contribute to cardioprotection.
Introduction
Remote ischemic preconditioning (RIPC) is a phenomenon
where preconditioning
Description
Keywords
Autonomic nervous system , blood flow , cardiac , ischemia , mote ischemic preconditioning