Protective Effect and Mechanism of Endogenous Antioxidant Metallothionein on Myocardial Damage Caused by Chronic Intermittent Hypoxia

Abstract

Abstract: Objective To determine whether zinc and sulforaphane (SFN) can play a protective role in myocardial injury induced by chronic intermittent hypoxia (CIH) through up-regulating the expression of metallothionein (MT) in myocardium,and to explore its mechanism. Methods 8-week-old male Kunming mice were randomly divided into control group, CIH group, CIH+N. S group, zinc protection group and SFN protection group. All of them were exposed to CIH environment except the control group to construct myocardial damage model induced by CIH. At the same time, the protection group and the normal saline group were injected with zinc sulfate (5 mg/kg), SFN (0.5 mg/kg) and the same volume of normal saline respectively. After 8 weeks, echocardiography, Sirius scarlet staining, immunohistochemistry and western blot were used to detect the cardiac structure and function of mice, the expression of collagen fibers, MT, nuclear factor E2 related factor 2 (Nrf2) and protein kinase B (Akt) in myocardial tissue. Results Compared with control group, CIH group showed ventricular dilation, decreased cardiac function and increased degree of myocardial fibrosis, the difference was statistically significant (P<0.05); Compared with CIH group, the dilation of heart, cardiac insufficiency and myocardial fibrosis of mice in zinc sulfate and SFN protection group were reduced, and the difference was statistically significant (P<0.05); Compared with CIH group, the expressions of MT, Nrf2 and Akt2 in myocardium of mice were increased in zinc sulfate and SFN protection group , and the differences were statistically significant (P<0.05). Conclusion CIH can cause myocardial injury in mice, and zinc and SFN have protective effects on CIH-induced myocardial injury, which may be related to the up-regulation of MT, Nrf2 and Akt2 expression.

Key words: chronic intermittent hypoxia, myocardial injury, metallothionein, nuclear factor E2 related factor 2, zinc sulfate, sulforaphane

CLC Number:

R542.2

WANG He-ru, YIN Xia, XIA Bin-feng, ZHENG Qing-shuang, CUI Ming-yue. Protective Effect and Mechanism of Endogenous Antioxidant Metallothionein on Myocardial Damage Caused by Chronic Intermittent Hypoxia[J]. ZHONGHUA YANGSHENG BAOJIAN, 2023, 41(24): 14-17.

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