The Beneficial Effects of Trimetazidine on Reperfusion–Induced Arrhythmia in Diabetic Rats

2018 ◽  
Vol 127 (05) ◽  
pp. 320-325 ◽  
Author(s):  
Fatemeh Ramezani-Aliakbari ◽  
Mohammad Badavi ◽  
Mahin Dianat ◽  
Seyed Mard ◽  
Akram Ahangarpour

AbstractTrimetazidine (TMZ), as an anti-ischemic drug, plays a critical role in protecting against cardiovascular complications induced by diabetes. This study was therefore aimed to evaluate the protective effects of TMZ on reperfusion-induced arrhythmias in the diabetic rats. Male Sprague-Dawley rats (250±20 g) were randomly assigned to four (n=8): control rats (C), alloxan induced diabetic rats (D), diabetic rats treated with TMZ (10 mg/kg, D+T10), diabetic rats treated with TMZ (30 mg/kg, D+T30). TMZ was treated orally once daily for 8 weeks. Diabetes was induced by a single intraperitoneal injection of alloxan (120 mg/kg). Ischemia-reperfusion (I/R) was carried out via 30 min of ischemia and following120-min reperfusion. The magnitude and score of arrhythmia, the left ventricular function, infarct size, lactate dehydrogenase (LDH), myocardial creatine kinase (CK-MB) and troponin (cTnI) were measured. The findings were evaluated by two-way repeated measures and one-way ANOVA followed by LSD post hoc test and Fisher's exact test for incidence percentage. The duration, incidence and score of arrhythmia (p<0.001), infarct size (p<0.01) were significantly increased, the cardiac contractility (±dp/dt), LDH, CK-MB (p<0.001) and cTnI (p<0.05) were significantly decreased in the diabetic rats in comparison with the control group. However, treatment with TMZ in the diabetic rats was significantly improved the duration (p<0.001), incidence and score of arrhythmia,±dp/dt LDH, CK-MB, cTnI (p<0.05) and infarct size (p<0.01) in comparison with the untreated diabetic group. The present study indicates anti-arrhythmic effect of TMZ in reducing arrhythmias induced by reperfusion in the diabetic rats.

2003 ◽  
Vol 95 (6) ◽  
pp. 2510-2518 ◽  
Author(s):  
David A. Brown ◽  
Korinne N. Jew ◽  
Genevieve C. Sparagna ◽  
Timothy I. Musch ◽  
Russell L. Moore

The effect of endurance training on the resistance of the heart to left ventricular (LV) functional deficit and infarction after a transient regional ischemia and subsequent reperfusion was examined. Female Sprague-Dawley rats were randomly assigned to an endurance exercise training (Tr) group or a sedentary (Sed) control group. After 20 wk of training, hearts were excised, perfused, and instrumented for assessment of LV mechanical function, and the left anterior descending coronary artery was occluded to induce a transient regional ischemia (1 h) that was followed by 2 h of reperfusion. Throughout much of the regional ischemia-reperfusion protocol, coronary flow rates, diastolic function, and LV developed pressure were better preserved in hearts from Tr animals. During the regional ischemia, coronary flow to myocardium outside the ischemic zone at risk (ZAR) was maintained in Tr hearts, whereas it progressively fell in Sed hearts. On release of the coronary artery ligature, flow to the ZAR was greater in Tr than in Sed hearts. Infarct size, expressed as a percentage of the ischemic ZAR, was significantly smaller in hearts from Tr rats (24 ± 3 vs. 32 ± 2% of ZAR, P < 0.05). Mn- and CuZn-SOD protein expression were higher in the LV myocardium of Tr animals ( P < 0.05 for both isoforms). Our data indicate that long-term exercise training leads to infarct sparing and better maintenance of coronary flow and mechanical function after ischemia-reperfusion.


2004 ◽  
Vol 287 (4) ◽  
pp. H1786-H1791 ◽  
Author(s):  
Shinji Okubo ◽  
Yujirou Tanabe ◽  
Kenji Takeda ◽  
Michihiko Kitayama ◽  
Seiyu Kanemitsu ◽  
...  

We examined whether ischemic preconditioning (IPC) attenuates ischemia-reperfusion injury, in part, by decreasing apoptosis and whether the δ-opioid receptor (DOR) plays a pivotal role in the regulation of apoptosis. Rabbits were subjected to 30-min coronary artery occlusion (CAO) and 180 min of reperfusion. IPC was elicited with four cycles of 5-min ischemia and 10-min reperfusion before CAO. Morphine (0.3 mg/kg iv) was given 15 min before CAO. Naloxone (Nal; 10 mg/kg iv) and naltrindole (Nti; 10 mg/kg iv), the respective nonselective and selective DOR antagonists were given 10 min before either morphine or IPC. Infarct size (%risk area) was reduced from 46 ± 3.8 in control to 11.6 ± 1.0 in IPC and 19.5 ± 3.8 in the morphine group (means ± SE; P < 0.001 vs. control). Nal blocked the protective effects of IPC and morphine, as shown by the increase in infarct size to 38.6 ± 7.2 and 44.5 ± 1.8, respectively. Similarly, Nti blocked IPC and morphine-induced protection. The percentage of apoptotic cells (revealed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay) decreased in IPC (3.6 ± 1.9) and morphine groups (5.2 ± 1.2) compared with control group (12.4 ± 1.6; P < 0.001). Nti pretreatment increased apoptotic cells 11.2 ± 2.2% in IPC and 12.1 ± 0.8% in morphine groups. Nal failed to block inhibition of apoptosis in the IPC group (% of cells: 5.7 ± 1.3 vs. 3.6 ± 1.9 in IPC alone; P > 0.05). These results were also confirmed by nucleosomal DNA laddering pattern. We conclude that IPC reduces lethal injury, in part, by decreasing apoptosis after ischemia-reperfusion and activation of the DOR may play a crucial role in IPC or morphine-induced myocardial protection.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Mahmood Khan ◽  
Iyyapu K Mohan ◽  
Damodhar Kumbala ◽  
Vijay K Kutala ◽  
Periannan Kuppusamy

Cytochrome P450 enzymes play a significant role in ischemia-reperfusion (I/R) injury. Sulfaphenazole (SFZ), a potent CYP2C9 inhibitor, is known to reduce I/R injury. However, the mechanism of its cardioprotective effects and the role of nitric oxide (NO) is not clear. Objective : Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are important mediators of I/R injury. The objective of this study was to determine how SFZ treatment modulates myocardial tissue oxygenation (pO 2 ) and RNS generation in vivo . Methods: Myocardial infarction was induced in rats by ligating the left anterior descending coronary artery (LAD) for 30 min, followed by 24 h of reperfusion. The study was divided into 4 groups: Untreated I/R control, SFZ, L-NAME, and SFZ+L-NAME. L-NAME (100 mg/kg/day), a nitric oxide synthase inhibitor, was given orally for 3 days prior to LAD ligation. SFZ (1.5 mg/kg, ip) was injected 30 min prior to LAD ligation. Oxygen-sensing crystals were implanted into the LV wall and the rat was placed in an L-band (1.2 GHz) electron paramagnetic resonance (EPR) spectrometer for measurement of myocardial tissue pO 2 during I/R injury. Hemodynamic data was collected with a microtip catheter. Infarct size was measured after 24 h of reperfusion. Superoxide generation was determined by dihydroethidium fluorescence imaging. Immunohistological staining was performed for nitrotyrosine and iNOS. Results: After LAD ligation, pO 2 decreased from 18 mmHg baseline to <2 mmHg. At reperfusion, there was a significant myocardial hyperoxygenation in SFZ-treated rats compared to control group (45.0±1.3 vs. 34.0±2.0 mmHg, P<0.05). In L-NAME and L-NAME+SFZ-treated rats, there was a significant reduction in pO 2 (24.0±1.6 and 26.0±2.3 mmHg, respectively). Compared to control, SFZ treatment significantly improved the left ventricular developed pressure (94.0±4.7 vs. 69.0±6.5 mmHg, P<0.05), decreased infarct size % (35.0±4.2 vs. 16.0±2.5, P<0.05), decreased superoxide generation and nitrotyrosine production. Conclusions: These findings demonstrate that SFZ may provide potent cardioprotection by attenuating post-ischemic ROS and RNS generation, and could serve as an attractive adjuvant therapy in the clinical setting of myocardial I/R injury.


2004 ◽  
Vol 286 (4) ◽  
pp. R751-R755 ◽  
Author(s):  
Daiyi Tang ◽  
Tianzheng Yu ◽  
Ali A. Khraibi

Diabetes mellitus (DM) is characterized by alterations in fluid balance and blood volume homeostasis. Renal interstitial hydrostatic pressure (RIHP) has been shown to play a critical role in mediating sodium and water excretion under various conditions. The objective of this study was to determine the effects of immediate and delayed initiation of insulin treatment on the restoration of the relationship between RIHP, natriuretic, and diuretic responses to acute saline volume expansion (VE) in diabetic rats. Diabetes was induced by an intraperitoneal injection of streptozotocin (STZ; 65 mg/kg body wt). Four groups of female Sprague-Dawley rats were studied: normal control group (C), untreated diabetic group (D), immediate insulin-treated diabetic group (DI; treatment with insulin for 2 wk was initiated immediately when diabetes was confirmed, which was 2 days after STZ injection), and delayed insulin-treated diabetic group (DDI; treatment with insulin for 2 wk was initiated 2 wk after STZ injection). RIHP and sodium and water excretions were measured before and during VE (5% body wt/30 min) in the four groups of anesthetized rats. VE significantly increased RIHP, fractional excretion of sodium (FENa), and urine flow rate (V) in all groups of rats. Basal RIHP, RIHP response to VE (ΔRIHP), and FENa and V responses to VE (ΔFENa and ΔV) were significantly lower in the D group compared with the C group of rats. ΔRIHP was significantly higher in both DI and DDI groups compared with D group but was similar to that of the C group of rats. While in the DI group the ΔFENa response to VE was restored, ΔFENa was significantly increased in DDI compared with D group, but it remained lower than that of the C group. In conclusion, insulin treatment initiated immediately after the onset of diabetes restores basal RIHP and RIHP, natriuretic, and diuretic responses to VE; however, delayed insulin treatment restores the basal RIHP and RIHP response to VE but does not fully restore the natriuretic response to VE.


2016 ◽  
Vol 310 (1) ◽  
pp. H104-H112 ◽  
Author(s):  
Ala'a Abwainy ◽  
Fawzi Babiker ◽  
Saghir Akhtar ◽  
Ibrahim F. Benter

The aim of the present study was to investigate the role of the ANG-(1–7) receptor (Mas) and nitric oxide (NO) in pacing postconditiong (PPC)-mediated cardioprotection against ischemia-reperfusion injury. Cardiac contractility and hemodynamics were assessed using a modified Langendorff system, cardiac damage was assessed by measuring infarct size and creatinine kinase levels, and levels of phosphorylated and total endothelial NO synthase (eNOS) were determined by Western blot analysis. Isolated hearts were subjected to 30 min of regional ischemia, produced by fixed position ligation of the left anterior descending coronary artery, followed by 30 min of reperfusion ( n = 6). Hearts were also subjected to PPC (three cycles of 30 s of left ventricular pacing alternated with 30 s of right atrial pacing) and/or treated during reperfusion with ANG-(1–7), NG-nitro-l-arginine methyl ester, or the Mas antagonist (d-Ala7)-ANG I/II (1–7). The PPC-mediated improvement in cardiac contractility and hemodyanamics, cardiac damage, and eNOS phosphorylation were significantly attenuated upon treatment with (d-Ala7)-ANG I/II (1–7) or NG-nitro-l-arginine methyl ester. Treatment with ANG-(1–7) improved cardiac function and reduced infarct size and creatinine kinase levels; however, the effects of ANG-(1–7) were not additive with PPC. In conclusion, these data provide novel insights into the cardioprotective mechanisms of PPC in that they involve the Mas receptor and eNOS and further suggest a potential therapeutic role for ANG-(1–7) in cardiac ischemic injury.


2004 ◽  
Vol 286 (5) ◽  
pp. H1923-H1935 ◽  
Author(s):  
James D. McCully ◽  
Hidetaka Wakiyama ◽  
Yng-Ju Hsieh ◽  
Mara Jones ◽  
Sidney Levitsky

Necrosis and apoptosis differentially contribute to myocardial injury. Determination of the contribution of these processes in ischemia-reperfusion injury would allow for the preservation of myocardial tissue. Necrosis and apoptosis were investigated in Langendorff-perfused rabbit hearts ( n = 47) subjected to 0 (Control group), 5 (GI-5), 10 (GI-10), 15 (GI-15), 20 (GI-20), 25 (GI-25), and 30 min (GI-30) of global ischemia (GI) and 120 min of reperfusion. Myocardial injury was determined by triphenyltetrazolium chloride (TTC) staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), bax, bcl2, poly(ADP)ribose polymerase (PARP) cleavage, caspase-3, -8, and -9 cleavage and activity, Fas ligand (FasL), and Fas-activated death domain (FADD). The contribution of apoptosis was determined separately ( n = 42) using irreversible caspase-3, -8, and -9 inhibitors. Left ventricular peak developed pressure (LVPDP) and systolic shortening (SS) were significantly decreased and infarct size and TUNEL-positive cells were significantly increased ( P < 0.05 vs. Control group) at GI-20, GI-25, and GI-30. Proapoptotic bax, PARP cleavage, and caspase-3 and -9 cleavage and activity were apparent at GI-5 to GI-30. Fas, FADD, and caspase-8 cleavage and activity were unaltered. Irreversible inhibition of caspase-3 and -9 activity significantly decreased ( P < 0.05) infarct size at GI-25 and GI-30 but had no effect on LVPDP or SS. Myocardial injury results from a significant increase in both necrosis and apoptosis ( P < 0.05 vs. Control group) evident by TUNEL, TTC staining, and caspase activity at GI-20. Intrinsic proapoptotic activation is evident early during ischemia but does not significantly contribute to infarct size before GI-25. The contribution of necrosis to infarct size at GI-20, GI-25, and GI-30 is significantly greater than that of apoptosis. Apoptosis is significantly decreased by caspase inhibition during early reperfusion, but this protection does not improve immediate postischemic functional recovery.


2014 ◽  
Vol 34 (2) ◽  
pp. 127-134 ◽  
Author(s):  
E Altinoz ◽  
Z Oner ◽  
H Elbe ◽  
Y Cigremis ◽  
Y Turkoz

The reactive oxygen species take role in pathogenesis of many diseases including hypoxia, hypercholesterolemia, atherosclerosis, nephropathy, hypertension, ischemia–reperfusion damage, and heart defects. The aim of this study was to evaluate whether crocin administration could protect kidney injury from oxidative stress in streptozotocin-induced diabetic rats. The rats were randomly divided into 3 groups each containing 10 animals as follows: group 1, control group; group 2, diabetes mellitus (DM) group; and group 3, DM + crocin group. At the end of the study, trunk blood was collected to determine the plasma levels of blood urea nitrogen (BUN) and creatinine (Cr). The kidney tissue was removed, and biochemical and histological changes were examined. Diabetes caused a significant increase in malondialdehyde (MDA) and xanthine oxidase (XO) activities and a decrease in glutathione (GSH) contents (  p < 0.01) when compared with control group in the rat kidneys. Crocin given to DM rats significantly decreased MDA (  p < 0.01) and XO (  p < 0.05) activities and elevated GSH (  p < 0.05) contents when compared with DM group. Plasma levels of BUN and Cr were significantly higher in the DM group when compared with the control group (  p < 0.01). Pretreatment of the DM animals with crocin decreased the high level of serum Cr and BUN. Control group was normal in histological appearance, but congestion, severe inflammation, tubular desquamation, tubular necrosis, and hydropic degeneration in tubular cells were observed in the DM group. Histopathological changes markedly reduced, and appearance of kidney was nearly similar to control group in DM + crocin group. Our results show that crocin could be beneficial in reducing diabetes-induced renal injury.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Palee ◽  
L Higgins ◽  
T Leech ◽  
S.C Chattipakorn ◽  
N Chattipakorn

Abstract Background Cardiac ischemia/reperfusion (I/R) injury following myocardial infarction reperfusion therapy is a phenomenon that results in further cardiomyocytes death and impaired cardiac contractility. Although metformin has been shown to exert cardioprotection in addition to glycemic control, its effect on cardiac I/R injury are still controversy, and the comparative doses of metformin in cardiac I/R injury have never been investigated. Purpose We hypothesized that metformin given acutely prior to cardiac ischaemia exerts cardioprotection in rats with cardiac I/R injury via attenuating cardiac mitochondrial dysfunction, leading to improved left ventricular (LV) function. Methods Forty Male Wistar rats were subjected to cardiac I/R injury. Four treatment groups were investigated. The first group received saline as a control group. The second to the fourth groups received metformin at 100, 200, and 400 mg/kg intravenously, respectively. During the I/R protocols, the LV function, arrhythmia score, and mortality rate were determined. At the end, the hearts were rapidly removed to determine infarct size, cardiac mitochondrial function, cardiac mitochondrial dynamics, and cardiac apoptosis. Results Metformin 200 mg/kg exerted the highest level of cardioprotection through the attenuated incidence of arrhythmia, decreased infarct size (Fig. 1), improved cardiac mitochondrial function, and decreased mitochondrial fission (Fig. 1) and cardiac apoptotic markers, leading to improved cardiac function during I/R injury. Although Metformin at all doses effectively decreased infarct size, improved cardiac mitochondrial function and LV function, Metformin at 200 mg/kg exerted the best efficacy (Fig. 1). Conclusions Metformin exerts cardioprotection by attenuating mitochondrial dysfunction and decreased mitochondrial fission, leading to decreased infarct size and ultimately improved LV function after acute cardiac I/R injury in rats. These findings also indicate the potential biphasic effects of metformin on infarct size which are dose-dependent. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Science and Technology Development Agency Thailand (NC), and Thailand Research Fund (SCC)


2021 ◽  
Author(s):  
Fang-Zheng Wang ◽  
Wen-Bo Wei ◽  
Xin Li ◽  
Jun-Yu Huo ◽  
Wan-Ying Jiang ◽  
...  

Abstract Background: Sodium-glucose cotransporter 2 inhibitor (SGLT2i) has been reported to improve glycaemic control in patients with type 2 diabetes. The aim of this study was to investigate the effect of SGLT2i Dapagliflozin (Dapa) on cardiomyopathy induced by isoproterenol (ISO) and its potential mechanism.Methods: Fifty male Sprague Dawley rats were randomly assigned to Control (n = 10) and ISO (2.5 mg/kg/day)-treated groups (n = 40). After 2 weeks, 28 survived rats with obvious left ventricular dysfunction in ISO group were randomized into three groups for medication including ARNI (angiotensin receptor neprilysin inhibitor, 68 mg/kg/day, n = 9), Dapa (3 mg/kg/day, n = 9) and ISO (saline, n = 10) for 4 weeks. After that, electrical programmed stimulation (EPS) was performed in all groups for the evaluation of the susceptibility of ventricular arrhythmias (VAs). Echocardiography was used to evaluate cardiac function. Results: Echocardiography revealed significant left ventricular (LV) dysfunction in rats with ISO treatment for 2 weeks compared to the control group. Dapa administration for 4 weeks reduced the cumulative risk of death, myocardial fibrosis, plasma angiotensin II level and its functional receptor AT1R protein expression in the heart, and proinflammatory cytokines levels in the cardiac tissue of ISO-treated rats. It also improved cardiac function and inhibited oxidative stress when compared to the ISO group. These effects were similar to ARNI. However, Dapa showed a greater efficacy than ARNI in reducing left ventricular end-diastolic volume, lowing heart rate and VAs, and decreasing body weight and plasma glucose in ISO-treated rats. Conclusion: Dapa effectively improved the myocardial remodelling and oxidative stress like ARNI in ISO-induced cardiomyopathy in rats, but Dapa may be more effectively in decreasing VAs, and improving cardiac function when compared to ARNI. The mechanisms by which Dapa exerts protective effects on cardiomyopathy may be related to its antioxidant capacity and hypoglycemic action.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jichun Han ◽  
Dong Wang ◽  
Bacui Yu ◽  
Yanming Wang ◽  
Huanhuan Ren ◽  
...  

The generation of reactive oxygen species (ROS) is a major cause of heart injury induced by ischemia-reperfusion. The left ventricular developed pressure (LVDP) and the maximum up/down rate of left ventricular pressure (±dp/dtmax⁡) were documented by a physiological recorder. Myocardial infarct size was estimated macroscopically using 2,3,5-triphenyltetrazolium chloride staining. Coronary effluent was analyzed for lactate dehydrogenase (LDH) and creatine kinase (CK) release to assess the degree of cardiac injury. The levels of C-reactive protein (CRP), interleukin-8 (IL-8), tumor necrosis factor-α(TNF-α), and interleukin-6 (IL-6) were analyzed to determine the inflammation status of the myocardial tissue. Cardiomyocyte apoptosis analysis was performed using the In Situ Cell Death Detection Kit, POD. Accordingly, licochalcone B pretreatment improved the heart rate (HR), increased LVDP, and decreased CK and LDH levels in coronary flow. SOD level and GSH/GSSG ratio increased, whereas the levels of MDA, TNF-α, and CRP and activities of IL-8 and IL-6 decreased in licochalcone B-treated groups. The infarct size and cell apoptosis in hearts from licochalcone B-treated group were lower than those in hearts from the I/R control group. Therefore, the cardioprotective effects of licochalcone B may be attributed to its antioxidant, antiapoptotic, and anti-inflammatory activities.


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