A study on the effect of non-excitatory electrical stimulation on myocardial ischemia-reperfusion injury in aged mice / 中华老年医学杂志

ABSTRACT

Objective:To investigate whether ventricular non-excitatory electrical stimulation(NES)preconditioning can protect myocardial ischemia-reperfusion(IR)injury in aged mice by regulating cardiac calcitonin gene-related peptide(CGRP).Methods:Male C57BL/6J mice were randomly divided into 3 groups, (1)the Sham group, receiving sham operation group(n=6); (2)the IR group, receiving ligation of coronary artery to induce myocardial ischemia for 45 min and reperfusion for 120 min(n=13); (3)the NES group, IR model receiving NES from 15 min before IR to the end of reperfusion(n=13). Infarct size was detected by staining with 2, 3, 5-triphenyltetrazolium chloride.The level of serum cTnI and expression of myocardial CGRP were measured by enzyme linked immunosorbent assay and quantitative real time polymerase chain reaction.Results:Compared with the IR group, the infarct sizes were significantly lower in NES group[(38.17±4.36)% vs.(45.33±5.68)%, P<0.05]. Besides, the IR and NES groups were associated with significantly increased levels of serum cTnI[(10.89±2.14)μg/L, (7.03±1.79)μg/L vs.(3.92±0.47)μg/L, P<0.001], myocardial CGRP protein[(26.33±4.55)μg/kg, (19.67±5.79)μg/kg vs.(17.00±2.90)μg/kg, P<0.01], CGRP mRNA[(1.40±0.20), (2.20±0.75) vs.(1.05±0.10), P<0.01]compared with the Sham group.Furthermore, the NES group was associated with markedly decreased levels of serum cTnI and myocardial CGRP protein, and increased level of CGRP mRNA compared with the IR group(all P<0.05). Conclusion:NES may protect myocardium IR injury by regulating endogenous CGRP expression in aged mice.