Postnatal development in intermittent hypoxia enhances resistance to myocardial ischemia/reperfusion in male rats

It is well known that insulin possesses a cardioprotective effect and that insulin resistance is closely related to cardiovascular diseases. Peroxynitrite (ONOO−) formation may trigger oxidative/nitrative stress and represent a major cytotoxic effect in heart diseases. This study was designed to investigate whether insulin attenuates ONOO− generation and oxidative/nitrative stress in acute myocardial ischemia/reperfusion (MI/R). Adult male rats were subjected to 30 min of myocardial ischemia and 3 h of reperfusion. Rats randomly received vehicle, insulin, or insulin plus wortmannin. Arterial blood pressure and left ventricular pressure were monitored throughout the experiment. Insulin significantly improved cardiac functions and reduced myocardial infarction, apoptotic cell death, and blood creatine kinase/lactate dehydrogenase levels following MI/R. Myocardial ONOO− formation was significantly attenuated after insulin treatment. Moreover, insulin resulted in a significant increase in Akt and endothelial nitric oxide (NO) synthase (eNOS) phosphorylation, NO production, and antioxidant capacity in ischemic/reperfused myocardial tissue. On the other hand, insulin markedly reduced MI/R-induced inducible NOS (iNOS) and gp91phox expression in cardiac tissue. Inhibition of insulin signaling with wortmannin not only blocked the cardioprotection of insulin but also markedly attenuated insulin-induced antioxidative/antinitrative effect. Furthermore, the suppression on ONOO− formation by either insulin or an ONOO− scavenger uric acid reduced myocardial infarct size in rats subjected to MI/R. We concluded that insulin exerts a cardioprotective effect against MI/R injury by blocking ONOO− formation. Increased physiological NO production (via eNOS phosphorylation) and superoxide anion reduction contribute to the antioxidative/antinitrative effect of insulin, which can be reversed by inhibiting phosphatidylinositol 3′-kinase. These results provide important novel information on the mechanisms of cardiovascular actions of insulin.

Download Full-text

Simvastatin Improves Myocardial Ischemia Reperfusion Injury through KLF-Regulated Alleviation of Inflammation

Disease Markers ◽

10.1155/2022/7878602 ◽

2022 ◽

Vol 2022 ◽

pp. 1-6

Author(s):

Tingju Wei ◽

Jun Li ◽

Guowei Fu ◽

Hui Zhao ◽

Chen Huang ◽

...

Keyword(s):

Myocardial Ischemia ◽

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Male Rats ◽

Cell Counting ◽

Inflammatory Factors ◽

Simvastatin Treatment ◽

Myocardial Ischemia Reperfusion Injury ◽

Myocardial Ischemia Reperfusion

Objective. To clarify the protective effect of simvastatin on myocardial ischemia reperfusion injury (MIRI) and the underlying mechanism. Materials and Methods. The MIRI model in rats was firstly constructed. Twenty-four male rats were randomly assigned into the sham group, ischemia-reperfusion (I/R) group, and simvastatin group, with 8 rats in each group. Contents of superoxide dismutase (SOD) and malondialdehyde (MDA), as well as serum levels of CK and inflammatory factors, in rats were determined by the enzyme-linked immunosorbent assay (ELISA). Lactate dehydrogenase (LDH) activity in the three groups was examined. Through flow cytometry and Cell Counting Kit-8 (CCK-8) assay, apoptosis and viability in each group were detected, respectively. Relative levels of HMGB1, Kruppel-like factor 2 (KLF2), eNOS, and thrombomodulin (TM) were finally determined. Results. Simvastatin treatment markedly enhanced SOD activity and reduced contents of MDA, LDH, and creatine kinase (CK) in MIRI rats. The increased apoptosis and decreased viability following MIRI were partially reversed by simvastatin treatment. Besides, MIRI resulted in the upregulation of inflammatory factors and chemokines. Their elevations were abolished by simvastatin. In MIRI rats, simvastatin upregulated KLF2 and p-eNOS. Conclusions. Simvastatin protects inflammatory response at post-MIRI through upregulating KLF2, thus improving cardiac function.

Download Full-text

Irbesartan ameliorate inflammatory responses, and apoptosis induced by myocardial ischemia/reperfusion in male rats

American Journal of BioMedicine ◽

10.18081/2333-5106/019-2/138-150 ◽

2019 ◽

Vol 7 (2) ◽

pp. 138-150

Author(s):

Najah R. Hadi ◽

Fadhil G. Al-Amran

Keyword(s):

Myocardial Ischemia ◽

Troponin I ◽

Inflammatory Responses ◽

Ischemia Reperfusion ◽

Cardiac Injury ◽

Male Rats ◽

Control Group ◽

Inflammatory Reactions ◽

Tnf Α ◽

Myocardial Ischemia Reperfusion

Myocardial ischemia–reperfusion (I-R) represents a clinically relevant problem associated with thrombolysis, angioplasty and coronary bypass surgery. This study was undertaken to investigate the potential role of Irbesartan in amelioration of myocardial I/R injury induced by ligation of coronary artery (LAD) in a rat model. We are pretreated the animals with Irbesartan 3mg/kg i.p. 30 minutes before ligation of LAD. At the end of experiment (2 h of reperfusion), blood samples were collected from the heart for measurement of plasma level of cardiac troponin I (cTn-I). Compared with the sham group, levels of myocardial TNF-α, IL-1β, IL-6, MCP-1, MIP-1 alpha, and plasma cTn-I were increased (P<0.05). Histologically, all rats in control group showed significant cardiac injury after I-R. Furthermore, rats in control group showed significant apoptosis. Irbesartan significantly counteract the increased in myocardium level of TNF-α, IL-1B, IL-6, MCP-1, MIP-1 alpha, plasma cTn-I and apoptotosis (P<0.05). Histological analysis revealed that Irbesartan markedly reduced the severity of heart injury in the rats underwent LAD ligation procedure. We concluded that Irbesartan may ameliorate myocardial I/R injury in rats via interfering with inflammatory reactions and apoptosis which induced by I/R injury.

Download Full-text

The cardioprotective potential of Tadalafil in myocardial ischemia/reperfusion

American Journal of BioMedicine ◽

10.18081/2333-5106/020-2/87-100 ◽

2020 ◽

Vol 8 (2) ◽

pp. 87-100

Author(s):

Najah R. Hadi ◽

Fadhil G. Al-Amran

Keyword(s):

Myocardial Ischemia ◽

Caspase 3 ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Cardiac Injury ◽

Male Rats ◽

Control Group ◽

Inflammatory Reactions ◽

Tnf Α ◽

Myocardial Ischemia Reperfusion

The objective of this study is to assess the potential protective effect of Tadalafil on myocardial ischemia reperfusion injury induced by LAD ligation, 28 male rats were randomized into 4 groups (7 rats per group); Sham, rats underwent the same anesthetic and surgical procedure except for LAD ligation; control, rats underwent LAD ligation for 30 minutes and reperfusion for 2 hours; vehicle, rats treated with 10% DMSO, the Tadalafil solvent 30 minutes before the ligation; Tadalafil group, rats pretreated with Tadalafil1mg/kg i.p 30 minutes before ligation. In control group, as compared with sham, tissue TNF-α, IL-6, IL-10, caspase-3 and BAX, plasma cTn-T and serum MDA significantly increased (P<0.05), while serum GSH significantly decreased (P<0.05). Histopathologically, control group showed a significant cardiac injury (P<0.05) compared with sham group. Tadalafil significantly counteracted (P<0.05) the increase of TNF-α, IL-6, caspase-3 and BAX and counteracted the increase in plasma cTn-T and serum MDA. Tadalafil produces a significant elevation (P<0.05) in cardiac IL-10 and serum GSH with significant reduction in (P<0.05) cardiac injury. In We concluded that Tadalafil attenuates myocardial I/R injury in male rats through interfering with inflammatory reactions and apoptosis .

Download Full-text