Effects of Chronic and Acute Zinc Supplementation on Myocardial Ischemia-Reperfusion Injury in Rats

Abstract

The present study aims to explore the effects of chronic and acute zinc sulfate supplementation on myocardial ischemia-reperfusion injury in rats. The study registered 50 adult male rats which were divided into five groups in equal numbers as follows: group 1, normal control; group 2, sham; group 3, myocardial ischemia reperfusion (My/IR): the group which was fed on a normal diet and in which myocardial I/R was induced; group 4, myocardial ischemia reperfusion + chronic zinc: (5 mg/kg i.p. zinc sulfate for 15 days); and group 5, myocardial ischemia reperfusion + acute zinc: the group which was administered 15 mg/kg i.p. zinc sulfate an hour before the operation and in which myocardial I/R was induced. The collected blood and cardiac tissue samples were analyzed using spectrophotometric method to determine levels of MDA, as an indicator of tissue injury, and GSH, as an indicator of antioxidant activity. The highest plasma and heart tissue MDA levels were measured in group 3 (p < 0.05). Group 5 had lower MDA values than group 3, while group 4 had significantly lower MDA values than groups 3 and 5 (p < 0.05). The highest erythrocyte GSH values were found in group 4 (p < 0.05). Erythrocyte GSH values in group 5 were higher than those in group 3 (p < 0.05). The highest GSH values in heart tissue were measured in group 4 (p < 0.05). The results of the study reveal that the antioxidant activity inhibited by elevated oxidative stress in heart ischemia reperfusion in rats is restored partially by acute zinc administration and markedly by chronic zinc supplementation.

Acute dietary zinc deficiency in rats exacerbates myocardial ischaemia–reperfusion injury through depletion of glutathione

“…Cardiac and plasma Zn levels are severely depleted in patients post-myocardial infarction, the extent of depletion correlating with myocardial infarction outcome (8) and with the levels of enzyme markers (lactate dehydrogenase and creatine kinase) of the extent of myocardial injury and the severity of arrhythmia (9) , leading to the proposal that Zn supplementation given at the time of reperfusion may represent a cardioprotective approach. Indeed, studies have shown that administration of Zn pyrithione at the time of reperfusion in isolated hearts can ameliorate reperfusioninduced injury via the reperfusion injury salvage kinase pathway (10) , improve post-reperfusion contractile recovery and reduce reperfusion-induced ventricular fibrillation (VF) (11) and, in hyperlipidaemic hearts, restore the infarct reducing effect of preconditioning (12) , while chronic Zn supplementation before I/R reduces infarct size and increases cardiac glutathione (GSH) content (13) . Conversely, studies looking at acute Zn depletion, using the Zn chelator TPEN (N,N,N′,N′-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine), demonstrate a worsening of infarct size (reviewed in Lee et al (7) ) but reduced arrhythmia severity (14,15) .…”

The inhibition of apoptosis through myocardial postconditioning by affecting Fas/FasIg signaling through miR139‐3p and miR181a‐1

“…After 30 minutes of ischemia, the clamp was opened and the silk passed through the tube was loosened to restore blood supply. These durations of I/R were already successfully used in the same experimental model 14–16 . In the PostC group, the artery was reperfused for 10 seconds following 30‐minute ischemia and then re‐occluded for 10 seconds.…”

“…These durations of I/R were already successfully used in the same experimental model. [14][15][16] In the PostC group, the artery was reperfused for 10 seconds following 30-minute ischemia and then re-occluded for 10 seconds. This procedure was repeated three times.…”

Sex differences in gene expression in response to ischemia in the human myocardium

“…RNA sequencing and preservation techniques have been detailed elsewhere. 55 Briefly, tissue samples were preserved in RNAlater ® (Ambion, Life Technologies, USA) immediately after collection and sequenced in batches at a later time-point on the Illumina HiSeq 2000 (Illumina, San Diego, CA). Paired-end reads 50, 90, or 100 base pairs long were generated, producing ~134 million reads per sample.…”