scholarly journals PEGylated Graphene Quantum Dot Improved Cardiac Function in Rats with Myocardial Infarction: Morphological, Oxidative Stress, and Toxicological Evidences

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Farzaneh Rostamzadeh ◽  
Mitra Shadkam-Farrokhi ◽  
Saeideh Jafarinejad-Farsangi ◽  
Hamid Najafipour ◽  
Zeinab Ansari-Asl ◽  
...  

Introduction. The biocompatibility and potential application of graphene-based nanomaterials in biomedicine have been documented. The effects of polyethylene glycol-graphene quantum dots (GQDs-PEG) on cardiac function in rats with myocardial infarction (MI) were examined. Methods. Wistar rats were randomly assigned to two main groups, each consisting of sham-Veh., MI-Veh., and MI+GQDs-PEG at doses of 5, 10, and 20 mg/kg. MI was induced by the closure of the left anterior descending (LAD) coronary artery. After MI, GQDs-PEG were injected at different doses IP every other day for two weeks. In the end, hemodynamic and heart contractility indices were assessed. The levels of myocardial MDA (malondialdehyde), SOD (superoxide dismutase), GPX (glutathione peroxidase), and TAC (total antioxidant capacity) were measured by the ELISA method. The serum ALP, ALT, AST, creatinine, and urea levels were measured using the photometric method. The infarct size was assessed by TTC staining. Results. GQDs-PEG decreased the infarct size at doses of 10 and 20 mg/kg and recovered the MI-induced reductions of +dp/dt max and -dp/dt max in the study groups. GQDs-PEG normalized systolic blood pressure and left ventricular systolic pressure reduction at the dose of 20 mg/kg in the MI group. Heart SOD, GPX, and TAC increased in the GQDs-PEG 10 and 20 groups. Almost no signs of toxic effects due to GQDs-PEG administration were observed on the liver and kidneys. Conclusions. The results provided clear evidence that GQDs-PEG improve cardiac performance and hemodynamic parameters in rats with MI by reducing oxidative stress. GQDs-PEG is proposed as a therapeutic target for the treatment of MI.

Author(s):  
Alexander B Veitinger ◽  
Audrey Komguem ◽  
Lena Assling-Simon ◽  
Martina Heep ◽  
Julia Schipke ◽  
...  

Abstract OBJECTIVES Esmolol-based cardioplegic arrest offers better cardioprotection than crystalloid cardioplegia but has been compared experimentally with blood cardioplegia only once. We investigated the influence of esmolol crystalloid cardioplegia (ECCP), esmolol blood cardioplegia (EBCP) and Calafiore blood cardioplegia (Cala) on cardiac function, metabolism and infarct size in non-infarcted and infarcted isolated rat hearts. METHODS Two studies were performed: (i) the hearts were subjected to a 90-min cardioplegic arrest with ECCP, EBCP or Cala and (ii) a regional myocardial infarction was created 30 min before a 90-min cardioplegic arrest. Left ventricular peak developed pressure (LVpdP), velocity of contractility (dLVP/dtmax), velocity of relaxation over time (dLVP/dtmin), heart rate and coronary flow were recorded. In addition, the metabolic parameters were analysed. The infarct size was determined by planimetry, and the myocardial damage was determined by electron microscopy. RESULTS In non-infarcted hearts, cardiac function was better preserved with ECCP than with EBCP or Cala relative to baseline values (LVpdP: 100 ± 28% vs 86 ± 11% vs 57 ± 7%; P = 0.002). Infarcted hearts showed similar haemodynamic recovery for ECCP, EBCP and Cala (LVpdP: 85 ± 46% vs 89 ± 55% vs 56 ± 26%; P = 0.30). The lactate production with EBCP was lower than with ECCP (0.6 ± 0.7 vs 1.4 ± 0.5 μmol/min; P = 0.017). The myocardial infarct size and (ECCP vs EBCP vs Cala: 16 ± 7% vs 15 ± 9% vs 24 ± 13%; P = 0.21) the ultrastructural preservation was similar in all groups. CONCLUSIONS In non-infarcted rat hearts, esmolol-based cardioplegia, particularly ECCP, offers better myocardial protection than Calafiore. After an acute myocardial infarction, cardioprotection with esmolol-based cardioplegia is similar to that with Calafiore.


2009 ◽  
Vol 37 (06) ◽  
pp. 1059-1068 ◽  
Author(s):  
Min Ge ◽  
Shanfeng Ma ◽  
Liang Tao ◽  
Sudong Guan

The relationship between changes of cardiac function and the gene expressions of two major myocardial skeleton proteins, titin and nebulin, and the effect of gypenosides on these gene expressions in diabetic cardiomyopathy rat were explored in the present study. Forty Sprague-Dawley rats were randomly divided into three groups: control group, diabetic cardiomyopathy group and gypenosides-treated diabetic cardiomyopathy group. The diabetic cardiomyopathy was induced in rats by injecting streptozotocin (STZ, 55 mg/kg) intraperitoneally. Seven weeks after the rats suffered from diabetes, the rats were treated with gypenosides 100 mg/kg per day orally for six weeks in gypenosides-treated group. In the meanwhile, the pure water was given to diabetic cardiomyopathy and the control groups. Subsequently, the cardiac functions, including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), ± dP/dtmax and t–dP/dmaxt, as well as the mRNA content and proteins of titin and nebulin in myocardium were determined. The results indicated that (1) the diabetic cardiomyopathy rats had decreased LVSP and ± dP/dtmax, increased LVEDP, and prolonged t–dP/dtmax than normal rats; (2) LVSP and ± dP/dtmax in diabetic cardiomyopathy rats treated with gypenosides were significantly higher and LVEDP and t–dP/dtmax were significantly lower than those without giving gypenosides; (3) the mRNA contents and proteins of titin and nebulin in diabetic cardiomyopathy rats were remarkably lower than those in the control rats and gypenosides had no effect on mRNA and protein expression levels of titin and nebulin in diabetic cardiomyopathy rats. We conclude that (1) the cardiac function as well as the mRNA expressions of titin and nebulin decreased in diabetic cardiomyopathy rats; (2) gypenosides secure cardiac muscles and their function from diabetic impairment and these beneficial effects of gypenosides are not by changing the expressions of titin and nebulin.


2003 ◽  
Vol 81 (2) ◽  
pp. 125-128 ◽  
Author(s):  
Ghada S Hassan ◽  
Fazila Chouiali ◽  
Takayuki Saito ◽  
Fu Hu ◽  
Stephen A Douglas ◽  
...  

Recent studies have shown that the vasoactive peptide urotensin-II (U-II) exerts a wide range of action on the cardiovascular system of various species. In the present study, we determined the in vivo effects of U-II on basal hemodynamics and cardiac function in the anesthetized intact rat. Intravenous bolus injection of human U-II resulted in a dose-dependent decrease in mean arterial pressure and left ventricular systolic pressure. Cardiac contractility represented by ±dP/dt was decreased after injection of U-II. However, there was no significant change in heart rate or diastolic pressure. The present study suggests that upregulation of myocardial U-II may contribute to impaired myocardial function in disease conditions such as congestive heart failure.Key words: urotensin-II, rat, infusion, heart.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Andreas Boening ◽  
Maximilian Hinke ◽  
Martina Heep ◽  
Kerstin Boengler ◽  
Bernd Niemann ◽  
...  

Abstract Background Because hearts in acute myocardial infarction are often prone to ischemia-reperfusion damage during cardiac surgery, we investigated the influence of intracellular crystalloid cardioplegia solution (CCP) and extracellular blood cardioplegia solution (BCP) on cardiac function, metabolism, and infarct size in a rat heart model of myocardial infarction. Methods Following euthanasia, the hearts of 50 rats were quickly excised, cannulated, and inserted into a blood-perfused isolated heart apparatus. A regional myocardial infarction was created in the infarction group (18 hearts) for 120 min; the control group (32 hearts) was not subjected to infarction. In each group, either Buckberg BCP or Bretschneider CCP was administered for an aortic clamping time of 90 min. Functional parameters were recorded during reperfusion: coronary blood flow, left ventricular developed pressure (LVDP) and contractility (dp/dt max). Infarct size was determined by planimetry. The results were compared between the groups using analysis of variance or parametric tests, as appropriate. Results Cardiac function after acute myocardial infarction, 90 min of cardioplegic arrest, and 90 min of reperfusion was better preserved with Buckberg BCP than with Bretschneider CCP relative to baseline (BL) values (LVDP 54 ± 11% vs. 9 ± 2.9% [p = 0.0062]; dp/dt max. 73 ± 11% vs. 23 ± 2.7% [p = 0.0001]), whereas coronary flow was similarly impaired (BCP 55 ± 15%, CCP 63 ± 17% [p = 0.99]). The infarct in BCP-treated hearts was smaller (25% of myocardium) and limited to the area of coronary artery ligation, whereas in CCP hearts the infarct was larger (48% of myocardium; p = 0.029) and myocardial necrosis was distributed unevenly to the left ventricular wall. Conclusions In a rat model of acute myocardial infarction followed by cardioplegic arrest, application of BCP leads to better myocardial recovery than CCP.


2020 ◽  
Author(s):  
Jianbing Zhu ◽  
Hang Chen ◽  
Yuanji Ma ◽  
Haibo Liu ◽  
Zhaoyang Chen

Abstract BackgroundNecrosis of ischemic cardiomyocytes after myocardial infarction (MI) activates an intense inflammatory reaction. Dendritic cells (DCs) play a crucial role in the repair process after MI. Tolerogenic DCs (tDCs) can inhibit inflammatory responses. Methods and resultsWe investigated the role of atorvastatin and supernatants of necrotic cardiomyocytes (SNC) on DCs. We found that SNC induced DCs maturation, activated TLR-4/NF-κB pathway, promoted inflammatory cytokines secretion and oxidative stress. Co-treatment with SNC and atorvastatin suppressed DC maturation and inflammatory response, which meant that atorvastatin induced DCs tolerate to SNC. Then, we investigated the effect of mDCs induced by SNC and tDCs induced by atorvastatin on ventricular remodeling after MI. tDCs treatment significantly improved the left ventricular systolic function, reduced the infiltration of MPO+ neutrophil, Mac3+ macrophages and CD3+ T cells, inhibited myocardial apoptosis and fibrosis, and decreased infarct size. Compared with PBS, treatment with mDCs did not showed beneficial effect on ventricular remodeling and inflammatory reaction after MI in mice.ConclusionAtorvastatin inactivated the TLR-4/NF-κB pathway, repressed the oxidative stress, inflammatory response, and immune maturity induced by SNC. Treatment with tDCs, induced by co-treated with atorvastatin, preserved left ventricular function, limited infarct size, suppressed the infiltration of inflammatory cells, and attenuated the severity of fibrosis, and reduced the number of apoptotic cardiomyocytes.


2020 ◽  
Author(s):  
Chong Du ◽  
Xiao-Wen Chen ◽  
Ze-Mu Wang ◽  
Hao-Yu Meng ◽  
Ya-Fei Li ◽  
...  

Abstract Background: Previous studies reported that hepatocyte growth factor (HGF) could promote angiogenesis and cardiac function after myocardial infarction (MI) in pigs. However, the results of these studies were controversial. To clarify the therapeutic efficacy of local HGF administration after MI, we performed a systematic review and meta-analysis of data from the pig models, which could provide evidence for the feasibility of clinical HGF application.Methods: PubMed, EMBASE, and China National Knowledge Infrastructure were searched for randomized studies that correspond to our subject. The search terms included (hepatocyte growth factor OR HGF) AND (heart failure OR HF OR myocardial infarction OR MI OR AMI OR coronary heart disease OR CHD). The primary endpoint indicators were identified as the left ventricular ejection fraction (LVEF) and capillaries density. Other parameters reflecting cardiac function and ventricular remodeling were analyzed as secondary indicators, including ventricular volume, infarct size, apoptotic index and others.Results: In total, 9 studies were finally included in the meta-analysis. On comparing the cardiac function indexes, the HGF group was found to be better than the control group in regard to LVEF, stroke volume, left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV). However, no statistically significant differences were found in heart rate. Furthermore, HGF treatment promotes angiogenesis in ischemic areas, which is manifested by increased capillary density. In addition, the HGF group was found to be better than the control group when it comes to infarct size, arteriole densities, and other indicators of cardiac remodeling.Conclusions: HGF treatment can effectively promote cardiac function and cardiac repair including angiogenesis, and this strategy is a promising cardio-protective approach that merits further clinical studies.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
J P Sousa ◽  
J Ribeiro ◽  
L Puga ◽  
C Lourenco ◽  
R Teixeira ◽  
...  

Abstract A 69-year-old man with history of non-insulin-treated type 2 diabetes mellitus, arterial hypertension and mixed dyslipidemia presented to the emergency department with chest pain lasting for four days. Immediate twelve-lead electrocardiogram unveiled an inferior ST-segment elevation myocardial infarction (STEMI), prompting emergent coronary angiography, which, in turn, revealed two-vessel disease, specifically proximal ramus intermedius 60-70% stenosis and proximal right coronary artery acute occlusion. Culprit lesion was successfully managed with balloon angioplasty and a single drug-eluting stent implantation. Still, clinical course was noticeable for deterioration, under the form of cardiogenic shock, which required invasive ventilation and intravenous vasopressor support with norepinephrine. Despite biventricular systolic function relative preservation, transthoracic echocardiography disclosed inferior akinesis, right ventricle dilation, mild circumferential pericardial effusion and, particularly, a 2.3cm posteroinferior ventricular septal defect (VSD), in the setting of a 4.4cm2 pseudoaneurism, resulting in left-to-right shunting, quantified through maximal/mean trans-VSD pressure gradients of 84/44mmHg. Further imaging with transesophageal echocardiography and cardiac computed tomography angiography allowing the conception of a 3D-printed model was performed. Surgical correction of the defect followed, achieving partial anatomic success, namely with residual shunting, as of a left ventricular systolic pressure of 80mmHg and a right ventricular systolic pressure of 25mmHg. Patient survived, recovered and got discharged three weeks later. At one-year follow-up, he was hospitalized for acute decompensated heart failure (hemodynamic profile C) twice, with medication non-adherence reported as the main precipitating factor. In addition to a significant remaining left-to-right shunt (maximal velocity 3m/s), adverse cardiac remodeling was recognized, featuring left ventricular ejection fraction of 30-35%, severe functional mitral regurgitation, severe postcapillary pulmonary hypertension and de novo left bundle branch block (QRS duration of 197ms). Having been deemed clinically unsuitable for another surgical correction, patient underwent percutaneous VSD closure with both AmplatzerTM septal and muscular VSD occluders, with a suboptimal result. He is now on New York Heart Association class III heart failure and on the waiting list for both MitraClip and cardiac resynchronization therapy implantation. Reflecting numerous breakthroughs in the management of acute myocardial infarction, incidence of mechanical complications is on the decline. Nevertheless, when they occur, morbidity and mortality remain high. Acquired ventricular septal defects are no exception, demanding the best care from a tertiary hospital heart team. Abstract P714 Figure.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Niek J. Pluijmert ◽  
Cindy I. Bart ◽  
Wilhelmina H. Bax ◽  
Paul H. A. Quax ◽  
Douwe E. Atsma

Abstract Many novel therapies to treat myocardial infarction (MI), yielding promising results in animal models, nowadays failed in clinical trials for several reasons. The most used animal MI model is based on permanent ligation of the left anterior descending (LAD) coronary artery in healthy mice resulting in transmural MI, while in clinical practice reperfusion is usually accomplished by primary percutaneous coronary interventions (PCI) limiting myocardial damage and inducing myocardial ischemia–reperfusion (MI-R) injury. To evaluate a more similar murine MI model we compared MI-R injury to unreperfused MI in hypercholesterolemic apolipoprotein (APO)E*3-Leiden mice regarding effects on cardiac function, left ventricular (LV) remodeling and inflammation. Both MI-R and MI resulted in significant LV dilation and impaired cardiac function after 3 weeks. Although LV dilation, displayed by end-diastolic (EDV) and end-systolic volumes (ESV), and infarct size (IS) were restricted following MI-R compared to MI (respectively by 27.6% for EDV, 39.5% ESV, 36.0% IS), cardiac function was not preserved. LV-wall thinning was limited with non-transmural LV fibrosis in the MI-R group (66.7%). Two days after inducing myocardial ischemia, local leucocyte infiltration in the infarct area was decreased following MI-R compared to MI (36.6%), whereas systemic circulating monocytes were increased in both groups compared to sham (130.0% following MI-R and 120.0% after MI). Both MI-R and MI models against the background of a hypercholesterolemic phenotype appear validated experimental models, however reduced infarct size, restricted LV remodeling as well as a different distributed inflammatory response following MI-R resemble the contemporary clinical outcome regarding primary PCI more accurately which potentially provides better predictive value of experimental therapies in successive clinical trials.


2008 ◽  
Vol 233 (10) ◽  
pp. 1280-1288 ◽  
Author(s):  
Yong Chun Jin ◽  
Kil Jung Kim ◽  
Young Min Kim ◽  
Yu Mi Ha ◽  
Hye Jung Kim ◽  
...  

Magnolol, an active component extracted from Magnolia officinalis, has been reported to have protective effect on ischemia and reperfusion (I/R)-induced injury in experimental animals. The aim of the present investigation was to further evaluate the mechanism(s) by which magnolol reduces I/R-induced myocardial injury in rats in vivo. Under anesthesia, left anterior descending (LAD) coronary artery was occluded for 30 min followed by reperfusion for 24 h (for infarct size and cardiac function analysis). In some experiments, reperfusion was limited to 1 h or 6 h for analysis of biochemical and molecular events. Magnolol and DMSO solution (vehicle) were injected intra-peritoneally 1 h prior to I/R insult. The infarct size was measured by TTC technique and heart function was monitored by Millar Catheter. Apoptosis related events such as p-ERK, p-Bad, Bcl-xl and cytochrome c expression were evaluated by Western blot analysis and myocardial caspase-3 activity was also measured. Magnolol (10 mg/kg) reduced infarct size by 50% ( P < 0.01 versus vehicle), and also improved I/R-induced myocardial dysfunction. Left ventricular systolic pressure and positive and negative maximal values of the first derivative of left ventricular pressure (dP/dt) were significantly improved in magnolol-treated rats. Magnolol increased the expression of phosphor ERK and Bad which resulted in inhibition of myocardial apoptosis as evidenced by TUNEL analysis and DNA laddering experiments. Application of PD 98059, a selective MEK1/2 inhibitor, strongly antagonized the effect of magnolol. Taken together, we concluded that magnolol inhibits apoptosis through enhancing the activation of ERK1/2 and modulation of the Bcl-xl proteins which brings about reduction of infarct size and improvement of cardiac function in I/R-induced injury.


Circulation ◽  
2005 ◽  
Vol 112 (9_supplement) ◽  
Author(s):  
Tomohiro Mizuno ◽  
Terrence M. Yau ◽  
Richard D. Weisel ◽  
Chris G. Kiani ◽  
Ren-Ke Li

Background— After a myocardial infarction, the injured region becomes fibrotic and the myocardial scar may expand if the ventricular wall lacks elasticity. Cardiac dilatation may precipitate the vicious cycle of progressive heart failure. The present study evaluated the functional benefits of increasing elastin within a myocardial scar using cell based gene therapy. Methods and Results— A myocardial infarction was generated by ligation of the left anterior descending artery in rats. Six days later, 2×10 6 syngeneic rat endothelial cells transfected with the rat elastin gene (elastin group, n=14) or an empty plasmid (control group, n=14) were transplanted into the infarct scar. Cardiac function, left ventricular (LV) volume, and infarct size were monitored over 3 months by echocardiography, Langendorff measurements, and planimetry. Elastin deposition was evaluated in the cells and in the infarct region by Western blot assay and by histological examination. Recombinant elastin was found in the scar in the elastin group but not the control group during the 3 months after cell transplantation. Histological assessment demonstrated organized elastic fibers within the infarct region. LV volume and infarct size were significantly smaller ( P <0.05) in the elastin group than in the control group. Cardiac function evaluated by echocardiography and during Langendorff perfusion was significantly better ( P <0.05) in the elastin group than in the control group. Conclusions— Expressing recombinant elastin within the myocardial scar reduced scar expansion and prevented LV enlargement after a myocardial infarction. Altering matrix remodeling after an infarct preserved the LV function for at least 3 months.


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