Protection by nitrite against the ischemic effects induced by acute myocardial infarction in mice

Soluble guanylate cyclase (sGC) stimulator vericiguat alleviates myocardial ischemia-reperfusion injury by improving microcirculation

Background

This study aimed to verify the effect of soluble guanylate cyclase (sGC) stimulator vericiguat on myocardial ischemia-reperfusion injury and explore its mechanism.

Methods

A myocardial ischemia-reperfusion injury model of mice was established and intravenous administration was performed 2 minutes before reperfusion. Triphenyltetrazolium chloride (TTC) staining and echocardiography were used to verify the effect of vericiguat on myocardial ischemia-reperfusion injury in the infarct area, and immunofluorescence was used to observe myocardial pathological changes at different time points after reperfusion. Quantitative proteomics was conducted to analysis the main differentially expressed proteins after drug intervention. The distribution of endothelial cells and sGC after myocardial ischemia-reperfusion injury in mice was observed by immunofluorescence. RNA sequencing of endothelial cells was used to search for differentially expressed molecules. Thioflavin-S staining was used to observe the effect of vericiguat on improving the nonrecurrence phenomenon and reducing the infarct size after reperfusion.

Results

The effect of the sGC stimulator vericiguat on myocardial ischemia-reperfusion injury was verified, and myocardial microcirculation significantly increased after drug intervention. Quantitative proteomics found that the protein expression of myocardial tissue in the ischemia-reperfusion area was not significantly different in the drug intervention group, except for increased adenosine triphosphate (ATP) activity. Vericiguat, nitroglycerin, and nitrite did not directly affect apoptosis or cell viability. RNA sequencing of human umbilical vein endothelial cells screened the upregulated antioxidant response.

Conclusions

SGC stimulator vericiguat ameliorated myocardial ischemia-reperfusion injury through indirect pathways of improving microcirculation.

Different Changing Patterns of Three NOS-NO System Activities after Ischemia-Reperfusion in Rabbit with AMI

NOS-NO system activity is closely correlated with ischemia-reperfusion injury (IRI) and NOS subtypes were suggested to play different roles in IRI. In this work, the activity of serum NOS, NO levels, and ischemic necrosis after reperfusion in rabbit with AMI at different time was studied. We also explored the NOS-NO system activity changes and its correlation with myocardial ischemia and necrosis. It shows that after reperfusion in rabbits with AMI, NO-NOS system activities present different changes at each time point due to inactivation of NO and iNOS activation, and different experimental animals, ischemia-reperfusion degree, and length of time will also lead to different research results. Therefore, it is necessary to conduct dynamic observation on animals from different species at multi-temporal point under the state of NOS-NO system activities, and simultaneously detect inflammatory factor, MDA, and SOD indexes. Therefore, it is a must to conduct relevant drug research studies to make NOS-NO system activities maintain the level in favor of ideal myocardial ischemia reperfusion.

Effect of pantoprazole on I-R-induced myocardial injury in diabetic rats targeting inflammatory cytokine release and oxidative stress

OBJECTIVES

To evaluate the pleiotropic potential and underlying mechanism of pantoprazole (PPZ) (common Proton Pump Inhibitors, PPIs) in type 2 diabetes mellitus (T2DM) -associated ischemia/reperfusion (I-R)-induced myocardial infarction which is still uncharted. Whereas some other PPIs have demonstrated their anti-diabetic, antioxidant, and anti-inflammatory potential.

MATERIALS AND METHODS

We evaluated the potential of coinciding treatment of PPZ (4 mg/kg/po/day for 8 weeks) in Wistar albino rats against STZ (50 mg/kg/IP) induced T2DM model and I-R provoked cardiac infarction model in diabetic and non-diabetic condition.

RESULTS

PPZ significantly inhibited the perturbed deviations in blood glucose concentration, HbA1c, C-peptide, plasma insulin, and ameliorated the lipid profile (dyslipidemia). PPZ protected myocardial tissue against lipid peroxidation by restoring the levels of serum TBARS and reduced NBT. The significant protective effects of PPZ were evident by ameliorating CKMB, LDH, cTnI, and myocardial oxidative stress in PPZ treated animals. Additionally, PPZ prominently reduced various proinflammatory cytokines release including TGF-β1, TNF-α, and IL-6. PPZ upsurges the bioavailability of nitrite/nitrate concentration which may pacify the impact of myocardial infarction in diabetic I-R injury.

CONCLUSION

The consequences indicate that PPZ possesses a potent protective effect against diabetic I-R-induced myocardial infarction via suppressing oxidative stress, inflammation, and dyslipidemia-associated tissue damage.