Trimetazidine protects against hypoxia-reperfusion-induced cardiomyocyte apoptosis by increasing microRNA-21 expression

Myocardial tissue injury caused by ischemia and hypoxia is a major cause of fatal diseases, including coronary atherosclerosis resulting from myocardial infarction and stroke. Trimetazidine (TMZ), as an anti-ischemic and antioxidant agent, has been demonstrated to preventing ischemia/reperfusion-induced cardiomyocyte apoptosis. However, the anti-apoptosis mechanism of TMZ has not been fully elucidated. The present study demonstrated that miR-21 involved trimetazidine-induced anti-apoptosis during H/R injury in H9C2 cell. In this study, TMZ increased miR-21 expression which further upregulated the Akt signaling activity via suppressing the expression of phosphatase and tensin homolog (PTEN) in H/R H9C2 cell. The increased activity of Akt signaling decreased the ratio of Bax/Bcl-2 and the expression of caspase-3 and inhibited H/R induced apoptosis. In conclusion, this study revealed the mechanism that TMZ up-regulated miR-21 expression, then miR-21 targeted PTEN increasing the PI3K pathway and finally the activation of this pathway counteracted the apoptotic effect of hypoxia/reperfusion.

Sirtuin 1 in rat orthotopic liver transplantation: An IGL-1 preservation solution approach

AIM: To investigate the possible involvement of Sirtuin 1 (SIRT1) in rat orthotopic liver transplantation (OLT), when Institute Georges Lopez 1 (IGL-1) preservation solution is enriched with trimetazidine (TMZ).

METHODS: Male Sprague-Dawley rats were used as donors and recipients. Livers were stored in IGL-1 preservation solution for 8h at 4 °C, and then underwent OLT according to Kamada’s cuff technique without arterialization. In another group, livers were stored in IGL-1 preservation solution supplemented with TMZ, at 10^-6 mol/L, for 8 h at 4 °C and then underwent OLT. Rats were sacrificed 24 h after reperfusion, and liver and plasma samples were collected. Liver injury (transaminase levels), mitochondrial damage (glutamate dehydrogenase activity) oxidative stress (malondialdehyde levels), and nicotinamide adenine dinucleotide (NAD⁺), the co-factor necessary for SIRT1 activity, were determined by biochemical methods. SIRT1 and its substrates (ac-FoxO1, ac-p53), the precursor of NAD⁺, nicotinamide phosphoribosyltransferase (NAMPT), as well as the phosphorylation of adenosine monophosphate activated protein kinase (AMPK), p-mTOR, p-p70S6K (direct substrate of mTOR), autophagy parameters (beclin-1, LC3B) and MAP kinases (p-p38 and p-ERK) were determined by Western blot.

RESULTS: Liver grafts preserved in IGL-1 solution enriched with TMZ presented reduced liver injury and mitochondrial damage compared with those preserved in IGL-1 solution alone. In addition, livers preserved in IGL-1 + TMZ presented reduced levels of oxidative stress. This was consistent with enhanced SIRT1 protein expression and elevated SIRT1 activity, as indicated by decreased acetylation of p53 and FoxO1. The elevated SIRT1 activity in presence of TMZ can be attributed to the enhanced NAMPT protein and NAD⁺/NADH levels. Up-regulation of SIRT1 was consistent with activation of AMPK and inhibition of phosphorylation of mTOR and its direct substrate (p-p70S6K). As a consequence, autophagy mediators (beclin-1 and LC3B) were over-expressed. Furthermore, MAP kinases were regulated in livers preserved with IGL-1 + TMZ, as they were characterized by enhanced p-ERK and decreased p-p38 protein expression.

CONCLUSION: Our study shows that IGL-1 preservation solution enriched with TMZ protects liver grafts from the IRI associated with OLT, through SIRT1 up-regulation.

Trimetazidine prevents oxidative changes induced in a rat model of sporadic type of Alzheimer's disease

Oxidative stress plays a major role in the pathogenesis of Alzheimer's disease (AD) of sporadic origin. The expression of DHCR24 (Seladin-1), marker for neuronal oxidative stress and degeneration, has been reported to be altered in the brains of AD patients. In the present study, we investigated the effect of trimetazidine (TMZ) on the hippocampal oxidative parameters and the expression of DHCR24 (Seladin-1) in an animal model of sporadic AD. Male rats were pre-treated with TMZ (25 mg/kg) after which injected with intracerebroventricular-streptozotocin (ICV-STZ)/Saline. Following 2, 7 and 14 days, animals of different groups were sacrificed with their brain excised to detect the hippocampal lipid peroxidation, superoxide dismutase (SOD), catalase activity, DHCR24 (Seladin-1) expression and possible histopathological changes. ICV-STZ administration induced significant oxidative changes in the hippocampus. Meanwhile, TMZ pre-treatment showed to ameliorate the oxidative stress, which was demonstrated by a significant rise in the hippocampal SOD and catalase activity, as well as a significant decrease in the malondialdehyde (MDA) level. TMZ administration also increased the expression of DHCR24 (Seladin-1) gene in the hippocampus. In conclusion, our findings indicated a neuroprotective effect of TMZ possibly related to its antioxidant activity resulting in the up-regulation of DHCR24 (Seladin-1). Such TMZ effects may be beneficial in minimizing oxidative stress in sporadic Alzheimer's disease and possible prevention of disease progression.

The effects of trimetazidine and sildenafil on bilateral cavernosal nerve injury induced oxidative damage and cavernosal fibrosis in rats

AIM

The aim of this study was to compare the effects of sildenafil and trimetazidine on bilateral cavernosal nerve injury-induced oxidative damage and fibrotic changes in cavernosal tissue in rat model.

MATERIAL AND METHODS

A total of 32 male Sprague-Dawley rats were randomly divided into 4 groups; each group consist 8 rats (control, BCI, BCI + TMZ, and BCI + sildenafil groups). Tissue superoxide dismutase (SOD), malondialdehyde (MDA), and protein carbonyl (PC) levels were determined biochemically and distribution of cavernosal fibrosis density among groups was performed histopathologically.

RESULTS

Tissue SOD levels in BCI group were significantly lower than the control group (P < 0.05). Tissue MDA and PC levels in BCI group were significantly higher than the control group (P < 0.05). TMZ and sildenafil administration significantly increased tissue SOD levels (P < 0.05) and reduced tissue MDA and PC levels (P < 0.05). Histologically, the degree of cavernosal fibrosis and collagen density was higher in BCI group in comparison to control, TMZ-treated, and sildenafil-treated groups.

CONCLUSION

BCI caused oxidative damage and increased cavernosal fibrosis in rat penis. TMZ and sildenafil treatment decreased oxidative damage and reduced the degree of fibrosis in penile tissue due to BCI.

AMPK involvement in endoplasmic reticulum stress and autophagy modulation after fatty liver graft preservation: a role for melatonin and trimetazidine cocktail

Ischemia/reperfusion injury (IRI) associated with liver transplantation plays an important role in the induction of graft injury. Prolonged cold storage remains a risk factor for liver graft outcome, especially when steatosis is present. Steatotic livers exhibit exacerbated endoplasmic reticulum (ER) stress that occurs in response to cold IRI. In addition, a defective liver autophagy correlates well with liver damage. Here, we evaluated the combined effect of melatonin and trimetazidine as additives to IGL-1 solution in the modulation of ER stress and autophagy in steatotic liver grafts through activation of AMPK. Steatotic livers were preserved for 24 hr (4°C) in UW or IGL-1 solutions with or without MEL + TMZ and subjected to 2-hr reperfusion (37°C). We assessed hepatic injury (ALT and AST) and function (bile production). We evaluated ER stress (GRP78, PERK, and CHOP) and autophagy (beclin-1, ATG7, LC3B, and P62). Steatotic livers preserved in IGL-1 + MEL + TMZ showed lower injury and better function as compared to those preserved in IGL-1 alone. IGL-1 + MEL + TMZ induced a significant decrease in GRP78, pPERK, and CHOP activation after reperfusion. This was consistent with a major activation of autophagic parameters (beclin-1, ATG7, and LC3B) and AMPK phosphorylation. The inhibition of AMPK induced an increase in ER stress and a significant reduction in autophagy. These data confirm the close relationship between AMPK activation and ER stress and autophagy after cold IRI. The addition of melatonin and TMZ to IGL-1 solution improved steatotic liver graft preservation through AMPK activation, which reduces ER stress and increases autophagy.

[Efficiency of trimetazidine treatment of experimental ischemic heart disease in age aspect]

Introduction of trimetazidine to 10-month-aged rats with experimental ischemic heart disease leads to an increase in carbohydrate utilization with energy purposes in myocardium, which is manifested by increasing activity of glycolysis enzymes with decreasing lactate level in myocardium, increasing activity of pyruvate dehydrogenase and citrate synthase in mitochondrial cardiomyocytes, and increasing ATP content in myocardium. This is accompanied by signs of stabilization of cardiomyocyte membranes and reduction in the degree of tissue hypoxia. The efficiency of trimetazidine decreases with increasing age: in 24-month-aged rats, the direction of changes is retained, but they are less pronounced.

Effect of diabetes on alteration of metabolism in cardiac myocytes: therapeutic implications

Diabetic cardiomyopathy is a distinct entity in humans. It leads to ventricular dysfunction independent of and additive to coronary artery disease and hypertension. Clinical and experimental studies have pointed to the role of metabolic derangements in the development of diabetic cardiomyopathy. Altered insulin signaling in diabetes leads to decreased myocyte glucose uptake and utilization, associated with an increased concentration of free fatty acids. This results in decreased glucose oxidation and increased fatty acid oxidation. Fatty acids increase mitochondrial oxygen consumption for ATP production and stimulate the uncoupling proteins in mitochondria. These proteins decrease the mitochondrial protein gradient, leading to fall in ATP production. The resultant defect in myocardial energy production impairs myocyte contraction and diastolic function. This is the hallmark of diabetic cardiomyopathy at earlier stages. In later stages diabetes impairs the myocyte ischemic defense mechanism, leading to increased cardiovascular morbidity and mortality. Other factors contributing toward causation of diabetic cardiomyopathy are collagen accumulation leading to reduced myocardial compliance, accumulation of advanced glycation end product-modified extracellular matrix proteins with subsequent inelasticity of vessel walls and myocytes, abnormal myocardial calcium handling leading to altered mechanics, endothelial dysfunction, cardiac autonomic neuropathy, and impairment of ischemic preconditioning. Trimetazidine acts a metabolic switch, favoring glucose over free fatty acids as the substrate for metabolism in cardiac myocytes.

Human obesity is characterized by defective fat storage and enhanced muscle fatty acid oxidation, and trimetazidine gradually counteracts these abnormalities

An impaired ability to store fatty acids (FA) in subcutaneous adipose tissue (SAT) may be implicated in the pathogenesis of obesity-related diseases via overexposure of lean tissues and production of free radicals from FA oxidation (FAO). We studied regional FA metabolism in skeletal muscle and adipose tissue in humans and investigated the long-term effects of the FAO inhibitor trimetazidine on glucose and FA metabolism. Positron emission tomography (PET) and [(11)C]palmitate were used to compare FA metabolism in SAT and skeletal muscle between eight obese and eight nonobese subjects (BMI ≥/< 30 kg/m(2)). A subgroup of nine subjects underwent a 1-mo trimetazidine administration. PET with [(11)C]palmitate and [(18)F]fluorodeoxyglucose, indirect calorimetry, and MRI before and after this period were performed to characterize glucose and FA metabolism, fat masses, skeletal muscle triglyceride, and creatine contents. Obesity was characterized by a 100% elevation in FAO and a defect in the FA esterification rate constant (P < 0.05) in skeletal muscle. FA esterification was reduced by ~70% in SAT (P < 0.001) in obese vs. control subjects. The degrees of obesity and insulin resistance were both negatively associated with esterification-related parameters and positively with FAO (P < 0.05). Trimetazidine increased skeletal muscle FA esterification (P < 0.01) and mildly upregulated glucose phosphorylation (P = 0.066). Our data suggest that human obesity is characterized by a defect in tissue FA storage capability, which is accompanied by a (potentially compensatory) elevation in skeletal muscle FAO; trimetazidine diverted FA from oxidative to nonoxidative pathways and provoked an initial activation of glucose metabolism in skeletal muscle.

[Stabilization of cellular membranes as a target of vascular therapy]

We present data of the study of effect of trimetazidine MB on the state of cellular membranes assessed on lymphocytes as highly sensitive model of hypoxia and endothelial dysfunction. Detection of external cytoplasmatic membrane blebbing and registration of quantity of membrane released microparticles by the method of phase-contrast microscopy were carried out in groups of patients with hypertensive disease without and with ischemic heart disease (IHD). It was found that number of cells in the state of terminal blebbing statistically significantly decreased and number of cells with intact cytoplasmic membrane increased at the background of intake of trimetazidine in all groups of patients. With correlation coefficient 0.76 (p&lt;0.05) between content of membrane microparticles and terminal blebbing lowering of content of membrane released microparticles was noted in peripheral blood of patients of all studied groups. The investigation conducted allows to make conclusion that stabilization of cellular membranes is one of spectra of trimetazidine actions underlying improvement of self feeling of patients with vascular pathology.

Effects of trimetazidine on endothelial dysfunction after sheath injury of radial artery

Transradial coronary artery angiography (TRCAG) can have harmful effects on the radial artery as a conduit for coronary artery bypass graft surgery. The aim of this study was to evaluate the effects of trimetazidine (TMZ) on the functional recovery of the radial artery in patients who underwent TRCAG with flow-mediated dilation (FMD). Sixty patients, who underwent TRCAG using a 5Fr sheath were randomly assigned to the TMZ group or the control group. Baseline, post-TRCAG (<24 hours after TRCAG), and 10-week follow-up FMD were performed. In the control group of the cannulated arm, the baseline FMD was 11.4 +/- 3.5%, but the post-TRCAG FMD was significantly decreased to 4.2 +/- 2.9% (p <0.01). At 10-week follow-up, FMD was still decreased compared to baseline FMD (11.4 +/- 3.5% vs 5.9 +/- 3.3%, p <0.01). In the TMZ group of the cannulated arm, the difference in FMD between baseline and post-TRCAG was also significant (11.3 +/- 3.5% vs 6.3 +/- 4.0%, p <0.01). However, at 10-week follow-up, FMD was improved to 10.4 +/- 3.4%, and there was no difference in FMD between baseline and 10-week follow-up (11.3 +/- 3.5% vs 10.4 +/- 3.4%, p = 0.26). Repeated-measures analysis of variance confirmed the significance of the differences in FMD between the TMZ group and the control group (p <0.01). In conclusion, TMZ therapy after TRCAG reduced the endothelial dysfunction of the radial artery. This could contribute to positive effects for the radial artery conduit after coronary artery bypass graft surgery.

Demand-induced ischemia in volume expanded isolated rat heart; the effect of dichloroacetate and trimetazidine

In failing hearts, coronary flow is normal, but the coronary flow reserve (CFR) is reduced, so demand-induced ischemia (DII) may occur in response to greater demand for O(2). The objectives of this study were: (i) to verify that dobutamine stimulation produces DII in isolated rat hearts having, like failing hearts, increased left ventricular end-diastolic pressure (LVEDP) and hence reduced CFR and (ii) to study the effects of stimulation of glucose oxidation and of inhibition of fatty acid oxidation in this new model of DII. Isolated rat hearts perfused with 11 mM glucose and 0.6 mM palmitate (or no palmitate) were studied. Stepwise increments in the volume of a balloon placed in LV resulted in reciprocal impairment of CFR, supporting the role of the extravascular compressive forces in determining CFR. CFR was 1.82+/-0.1 and 1.32+/-0.1 (p<0.05) in the hearts with LVEDP set to 5 mmHg (controls) and 40 mmHg (expanded), respectively. In controls, dobutamine increased coronary flow, myocardial oxygen consumption (MVO(2)), LVDP, mechanical efficiency, and the rates of palmitate and glucose oxidation, however, the effluent lactate concentration remained unchanged. In the expanded hearts vs. controls, dobutamine-induced increases in coronary flow and MVO(2) were reduced by approximately 50%, the increases in LVDP, efficiency, and rates of glucose and fatty acid oxidation were completely prevented, and lactate production greatly increased with dobutamine, indicating DII. Pyruvate dehydrogenase activator, dichloroacetate (DCA 1 mM) and a putative inhibitor of fatty acid beta-oxidation, trimetazidine (5 microM), both increased the rate of glucose oxidation and attenuated myocardial lactate production during DII, however they did not improve myocardial function during DII. Likewise, palmitate-free perfusion had no beneficial effect during DII although it attenuated lactate production. In the hearts subjected to palmitate-free perfusion plus DCA, lactate overproduction during DII was completely abolished, however, the deterioration of LVDP and mechanical efficiency was only partially prevented. Thus, greater demand for O(2) induces DII in the expanded hearts with reduced CFR. Lactate overproduction secondary to an imbalance between glycolysis and glucose oxidation is not a primary factor adversely affecting cardiac mechanical function during DII. Interventions shifting this balance toward glucose oxidation are not beneficial in the setting of DII in our model although they are known to effectively mitigate contractile dysfunction in the post-ischemic myocardium.

Trimetazidine and N-acetylcysteine in attenuating hind-limb ischemia and reperfusion injuries: experimental study in rats

AIM

Lower-limb traumatic injury associated with ischemia and followed by reperfusion (I/R) is a common severe situation in muscle lesions due to trauma and hypoxia followed by local and systemic injuries induced by oxygen-derived free radical release during reperfusion. The aim of this study was to evaluate the attenuating effects of trimetazidine (TMZ) and N-acetylcysteine (NAC) in such situation.

METHODS

The muscles at the root of the right hind limb of Wistar rats were cross-sectioned, preserving femoral vessels and nerves and clamping the femoral artery for four hours. The clamp was then released and the femoral artery has been reperfused for 2 hours. Rats were randomly divided in groups of ten as follows: Group 1: sham I/R, treated with saline; Group 2: I/R, treated with saline; Group 3: sham I/R, treated with TMZ (7.5 mg/kg/dose); Group 4: sham I/R, treated with NAC (375 mg/kg/dose); Group 5: I/R treated with TMZ (7.5 mg/kg/dose); Group 6: I/R treated with NAC (375 mg/kg/dose). All rats received two intravenous bolus injections of the drugs, one before ischemia and one before reperfusion. Oxidative stress in plasma (MDA, total, oxidized and reduced glutathione), creatinephosphokinase (CPK), optical and electron microscopy and pelvic extremity circumference and volume were studied.

RESULTS

No statistical differences were found between the groups for MDA or total and reduced glutathione. Oxidized glutathione increased significantly in groups 5 and 2. Limb circumference as well as limb volume increased in all groups over time, mainly in groups 5, 2 and 1. CPK increased in all groups, being highest in groups 5, 6 and 2. Histological lesions were present in all but sham groups, being less severe in group 6. Soleus muscle analyses at electron microscopy exhibit some degree of alteration in all groups.

CONCLUSIONS

This experimental model simulated severe limb trauma associated with ischemia and reperfusion, and, as such, it was aggressive, causing severe injury and local inflammatory reaction. The model did not show antioxidant action from NAC, and possible antioxidant action from TMZ was insufficient to attenuate tissue injuries.

Evaluation of putative inhibitors of mitochondrial permeability transition for brain disorders--specificity vs. toxicity

Inhibition of mitochondrial permeability transition (mPT) has emerged as a promising approach for neuroprotection and development of well-tolerated mPT inhibitors with favorable blood-brain barrier penetration is highly warranted. In a recent study, 28 clinically available drugs with a common heterocyclic structure were identified as mPT inhibitors e.g. trifluoperazine, promethazine and nortriptyline. In addition, neuroprotection by structurally unrelated drugs e.g. neurosteroids, 4-hydroxy-tamoxifen and trimetazidine has been attributed to direct inhibition of mPT. The regulation of mPT is complex and highly dependent on the prevailing experimental conditions. Several features of mPT, such as swelling, depolarization or NADH oxidation, can also occur independently of the mPT phenomenon. Here, in isolated rodent brain-derived and human liver mitochondria, we re-evaluate drugs promoted as potent mPT inhibitors. We address the definition of an mPT inhibitor and present strategies to reliably detect mPT inhibition in vitro. Surprisingly, none of the 12 compounds tested displayed convincing mPT inhibition or effects comparable to cyclophilin D inhibition by the non-immunosuppressive cyclophilin inhibitor D-MeAla(3)-EtVal(4)-Cyclosporin (Debio 025). Propofol and 2-aminoethoxydiphenyl borate (2-APB) inhibited swelling in de-energized mitochondria but did not increase calcium retention capacity (CRC). Progesterone, trifluoperazine, allopregnanolone and 4-hydroxy-tamoxifen dose-dependently reduced CRC and respiratory control and were thus toxic rather than beneficial to mitochondrial function. Interestingly, topiramate increased CRC at high concentrations likely by a mechanism separate from direct mPT inhibition. We conclude that a clinically relevant mPT inhibitor should have a mitochondrial target and increase mitochondrial calcium retention at concentrations which can be translated to human use.

[Effects of Trimetazidine upon ventricular remodeling and GLUT4 in diabetic rats after myocardial infarction]

OBJECTIVE

The aim of study is to investigate the changes of structure and function of heart in diabetic rat after myocardial infarction, and to study the expression of the GLUT4 and the effects of trimetazidine on the ventricular remodeling.

METHODS

Type 2 diabetes rat was made by feeding with a diet enriched with sucrose, fat and cholesterol for six weeks and then injecting streptozocin intraperitoneally, then the myocardial infarction by ligating coronary artery. The living rats were randomly divided into three groups twenty-four hours after operation: placebo; trimetazidine and sham operated with diabetes. And other rats which was fed with normal diet were divided into myocardial infarction group without diabetes and sham operated group without diabete. The treat group was intragastric administrated with trimetazidine which was solved in distilled water (30 mgxkg(-1) 1xd(-1)), and others were poured with parts aequalis distilled water. After six weeks, echocardiographic and hemodynamic studies were performed, ventricular were weighed, myocardial infarct size and myocardial collagen volume fraction (CVF) of non-infarction area were detected also. GLUT4 mRNA in the myocardium away from infarction region were measured with fluorescent quantitation RT-PCR and GLUT4 protein were measured with Western blot.

RESULTS

Six weeks after diabetes complicating with myocardial infarction, comparing with sham operated group without diabete, diabetes sham operated group and myocardial infarction group without diabete, LVDd of diabetes complicating with myocardial infarction group was increased significantly; the systolic and diastolic function with left ventricular were decreased significantly, VWI and CVF were increased significantly; comparing with placebo group, diastolic function of left ventricular in trimetazidine group was improved significantly (4.7 +/- 1.7 vs 6.8 +/- 1.6, P < 0.05); CVF (3.9 +/- 0.2)% vs (6.3 +/- 0.4)%, (P < 0.05) was decreased significantly, but LVDd, VWI and the systolic function was not chang significantly. The expression of GLUT4 mRNA and protein in sham operated with diabetes and diabetic with myocardial infarction descended significantly compared with sham operated group without diabete (P < 0.01). And in trimetazidine group, GLUT4 protein moderately increased (P < 0.05) compared with placebo group.

CONCLUSION

Trimetazidine could improve the diastolic function of left ventricular. The expression of GLUT4 mRNA and protein in type 2 diabetes complicating with myocardial infarction decreased. Trimetazidine could improve the expression of GLUT4 mRNA and protein in diabetes complicating with myocardial infarction and inhibited myocardial fibrosis.

Effect of trimetazidine on quality of life in elderly patients with ischemic dilated cardiomyopathy

INTRODUCTION

Elderly patients have an increased incidence of ischemic dilated cardiomyopathy, often related to diffuse coronary artery disease. Data have been cumulated to suggest that trimetazidine improves myocardial ischemia in patients with ischemic heart disease and improves left ventricular function in elderly patients with ischemic cardiomyopathy. The purpose of the present study was to assess the effects of trimetazidine in addition to standard cardiovascular therapy on left ventricular function and quality of life (QOL) parameters in elderly patients with ischemic heart disease and reduced left ventricular function.

METHODS

Patients were randomized to receive either trimetazidine (twice daily) or placebo (twice daily) in addition to standard therapy, and were evaluated at baseline and after 6 months.

RESULTS

Forty-seven patients completed the study (40 male, seven female; mean [+/-SD] age 78+/-3.4 years). Demographic data were comparable between the two groups with respect to sex, age, and race. At 6 months there was a significant improvement in the number of angina episodes per week in the trimetazidine group (-2.3+/-1, P=0.023). The overall assessment of QOL by a visual analog scale showed an improvement in patients randomized to trimetazidine at 6 months (from 4.1+/-0.6 to 6.4+/-0.8, P<0.01) and no changes in patients randomized to placebo (from 4.3+/-0.7 to 4.2+/-0.9, P>0.05). Physical QOL, evaluated by a MacNew Quality of Life After Myocardial Infarction questionnaire (MacNewQLMI), improved in patients randomized to trimetazidine but not in those allocated to placebo (32%+/-5% vs. -1%+/-3%, P<0.01). Similar results were obtained on social QOL evaluated by MacNewQLMI with trimetazidine compared with placebo (39%+/-4% vs. -2%+/-5%, P<0.01).

CONCLUSION

In elderly patients with ischemic heart disease and reduced ventricular function, trimetazidine improves clinical condition and QOL.

Effects of carvedilol, losartan and trimetazidin on functional parameters of isolated heart of rats at oxidative stress

Effects of carvedilol, lozartan and trimetazidin on functional parameters of isolated heart (heart rate and volume speed of coronary blood flow) of rats at oxidative stress have been studied with the use of Langendorf's method. Experiments have been carried out on 32 pubertal white rats (with body mass 220-250 g). Oxidative stress was induced through perfusion of hydrogen peroxide (with concentration - 4.10 -5 M). Obtained results were analyzed statistically according to the Student's t criterion. Studies have shown that carvedilol and trimetazidin have well expressed antioxidant and cardio protective effects at oxidative stress provoked by hydrogen peroxide compared to lozartan. Moreover, effect of carvedilol on HR and VsCBf was especially obvious than effects of Trimetazidin. Antioxidant and positive treatment effects of carvedilol could be explained by its wide range of pharmacological ability: as nonselective beta-adrenoblocker (via inhibition of adenylatecyclase and decreasing cyclic adenosinemonophosphate), alpha 1-adrenoblocker (decreasing activation of phospholipase C and concentration of inositoltriphosphate, diacylglicerole and Ca(++)) and antioxidant. It is suggested that positive effects of carvedilol on HR and VsCBf at oxidative stress are related with wide range of pharmacological mechanisms of preparation. Cardio protective effects of carvedilol at oxidative stress (revealed in our experiments) along with other positive cardio - hemodynamic peculiarities perhaps is very important and could be used successfully at treatment of cardio-vascular system diseases.

[Principle energy substrate changing as a technique of myocardium protection against ischemic damage in experimental mechanic cardiac contusion]

By changing the principal energy substrate, trimetasidine has reduced severity of ischemic myocardial damage as shown by greater integrity of membrane structures, improvement of contractile and rhythmic functions, central hemodynamics and lethality early after experimental myocardial contusion.

[Effects of chronic trimetazidine treatment on atrial energy metabolism in a canine model of chronic atrial fibrillation]

OBJECTIVE

Aim of the present study was to investigate the effect of chronic trimetazidine treatment on atrial energy metabolism and endothelial function in a canine model of chronic atrial fibrillation (AF).

METHODS

Eighteen canines were randomly divided into sham-operated group (n = 6), atrial pacing group (n = 6), and trimetazidine group (n = 6). In atrial pacing group and trimetazidine group, dogs were atrial paced at 400 beats per minutes for 6 weeks. Trimetazidine at 5 mgxkg(-1)xd(-1) was given one day before rapid atrial pacing for 6 weeks. Creatine phosphate (CrP), adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in atrial tissue were analyzed by high-performance liquid chromatography. Total adenosine (TAN) was calculated. The expression of endothelial nitric oxide synthase (eNOS) in atrial tissue was determined by Western blot and immunohistochemical staining. In addition, plasma levels of von Willebrand factor (vWF) was quantified with enzyme-linked immunoadsorbent assay and NO(2)(-)/NO(3)(-) (NOx) was determined by nitrate reductase method.

RESULTS

Atrial CrP (P < 0.01) and CrP/ATP were significantly decreased in paced atrium compared to atrium from sham-operated group (P < 0.05) while ATP, ADP, AMP and TAN remained unchanged (all P > 0.05). Plasma vWF was significantly increased and plasma NOx significantly decreased in paced animals compared to sham-operated animals. Atrial expression of eNOS was also significantly reduced in paced animals (P < 0.01). Trimetazidine treatment did not alter the contents of CrP, ATP, ADP, AMP and TAN, but significantly increased atrial eNOS expression (P < 0.05), decreased plasma vWF (P < 0.01) and increased plasma NOx concentration.

CONCLUSION

Trimetazidine treatment affect chronic AF induced disturbance in energy metabolism but may improve endothelial function through a NOx depended manner.

Central lipoprivation-induced suppression of luteinizing hormone pulses is mediated by paraventricular catecholaminergic inputs in female rats

The present study aims to clarify the role of fatty acids in regulating pulsatile LH secretion in rats. To produce an acute central lipoprivic condition, mercaptoacetate (MA), an inhibitor of fatty acids oxidation, was administered into the fourth cerebroventricle (4V) in ad libitum fed ovariectomized (OVX) rats (0.4, 2, and 10 micromol/rat) with or without an estradiol (E2) implant producing diestrus plasma E2 levels. Pulsatile LH secretion was suppressed by 4V MA administration in a dose-dependent manner in both OVX and OVX plus E2 rats. Mean LH levels and LH pulse frequency and amplitude were significantly reduced by the highest dose of MA in OVX rats, and by the middle and highest dose of MA in E2-treated rats, suggesting that estrogen enhanced LH suppression. Blood glucose levels increased immediately after the highest dose of MA in both groups. Fourth ventricular injection of trimetazidine (2 and 3 micromol/rat), another inhibitor of fatty acids oxidation, also inhibited pulsatile LH release, resulting in significant and dose-dependent suppression of LH pulse frequency and an increase in blood glucose levels in OVX plus E2 rats. In contrast, peripheral injection of the highest 4V dose of MA (10 micromol/rat) did not alter LH release or blood glucose levels. Microdialysis of the hypothalamic paraventricular nucleus (PVN) revealed that norepinephrine release in the region was increased by 4V MA administration. Preinjection of alpha-methyl-p-tyrosine, a catecholamine synthesis inhibitor, into the PVN completely blocked the lipoprivic inhibition of LH and the counter-regulatory increase in blood glucose levels in OVX plus E2 rats. Together, these studies indicate that fatty acid availability may be sensed by a central detector, located in the lower brainstem to maintain reproduction, and that noradrenergic inputs to the PVN mediate this lipoprivic-induced suppression of LH release.

The pathophysiology of heart failure: a tale of two old paradigms revisited

Although our current appreciation of the detrimental role of neurohumoral activation in heart failure (HF) has been intellectually appealing and has led to neurohumoral antagonism that has reduced morbidity and mortality from HF, the persisting disability and death rates remain unacceptably high. In the search for novel strategies to improve on these outcomes, we must reacquaint ourselves with basic cardiac physiology at levels ranging from the molecular to the systemic in order to identify new targets for the treatment of HF. This approach has already begun to yield results; in this review, two such aspects will be focused on: diastolic ventricular interaction and cardiac energetics. These two examples will be used to illuminate how fundamental research has elucidated age-old, although mechanistically elusive, principles (for example, the Frank-Starling law), explained why existing and emerging therapeutic approaches (for example, biventricular pacing in HF) have proved successful, and successfully identified novel therapy modes (for example, perhexiline as an energy augmentation agent).

[Effect of combination therapy with preduktal and prestarium on the left ventricular function in the postinfarction period]

The aim of the study was to estimate the efficiency of combination therapy with Preductal and Prestarium after MI. We investigated 152 patients with acute MI of anterior wall (Q wave) and Heart Failure (II-III class by NYHA). I group included 92 p, which were treated by Preductal (60 mg daily) on the background of the standard therapy. II group (60 p) treated by standard therapy. (ACE inhibitor, diuretic, beta-blocks). We divided the patients in 2 subgroups, with EF>45% and EF<45%. Echo investigation was performed after 1,3,6.12 months from the beginning of MI. We estimated LV EDV and ESV, EF, FS, SV and diastolic function. 12 month after myocardial infarction decreases of average heart failure and angina classes. After 6,12 months was noted decreased EDV and ESV, increased EF, FS,SV in both groups confidence, but spatially in the I gr. Patients, who had EF<45% and were treated with Preductal improved EF with 30,1%(p<0,05) confidence, which was 1,5 times more then in the control gr, also increased FS and SV by 32,7%, 13,6% p<0,05. At the same time was observed diastolic function improvement, particular decreased Ve, Ve/Va, and increased Va specially in the Preductal group more intensive and confidence. The treatment with Preductal during 12 months indicates his positive influence on the LV systolic and diastolic function, which is most significant in the patients with low EF.

The effect of trimetazidine on left ventricular systolic function and physical tolerance in patients with ischaemic cardiomyopathy

OBJECTIVE

Trimetazidine (TMZ) is the first of novel antianginal drugs with a cardioprotective effect, selectively inhibiting mitochondrial long-chain 3-ketoacyl coenzyme A thiolase. This study tested the hypothesis that the cytoprotective beneficial effect of this agent can lead to the improvement of left ventricular (LV) systolic function and tolerance to physical activity in patients with ischaemic cardiomyopathy.

METHODS AND RESULTS

In 82 consecutive patients with ischaemic cardiomyopathy, a subgroup of patients (n = 42) was assigned to receive a modified form of TMZ (35 mg twice daily) in addition to the conventional therapy for the duration of three months. All patients underwent clinical, echocardiographic examination and a six-minute walk test at baseline and after a three-month treatment. The therapy with TMZ significantly improved the functional class in these patients. Left ventricular ejection fraction (LVEF) increased by 3.5 +/- 6.72% (from 34.5 +/- 3.8% to 38.0 +/- 4.8%) in the TMZ group vs. 0.8 +/- 8.06% (from 32.4 +/- 5.6% to 33.2 +/- 5.8%) in the control group (P = 0.05). The tolerance to physical activity improved by 30.0 +/- 20.7 m in the TMZ group (from 215 +/- 17.5 m to 245 +/- 20.7 m) vs. 2.0 +/- 18.85 m (from 208.2 +/- 12.4 m to 210.2 +/- 14.2 m) in the control group (P < 0.001).

CONCLUSIONS

A therapeutic intervention with TMZ in conjunction with the standard therapy, over a three-month period, is associated with an increase in LVEF and improved tolerance to physical activity in patients with ischaemic cardiomyopathy.

Trimetazidine modulates AMPA/kainate receptors in rat vestibular ganglion neurons

Trimetazidine (1[2,3,4-trimethoxy-benzyl] piperazine, 2 HCl) is an anti-ischemic agent frequently administered as a prophylactic treatment for episodes of angina pectoris and chorioretinal disturbances. It is also employed as a symptomatic treatment of vertigo but its mechanism of action is yet to be defined. Using Fura-2 fluorescence photometry and whole-cell patch-clamp recordings we investigated the effect of trimetazidine on the [Ca(2+)](i) and current responses induced by the application of non-N-methyl-D-aspartate (NMDA) receptor agonists on low density vestibular ganglion neuronal cultures explanted from 3 day s postnatal rats. Trimetazidine blocked the [Ca(2+)](i) and current responses induced by 100 microM applications of both kainate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA). These responses were dependent on external Ca(2+) and were blocked by the voltage-dependent Ca(2+) channel blockers Ni(2+) and Cd(2+) . Trimetazidine only acts on the AMPA/kainate receptors and had no effect on K(+)-induced depolarizations. Dose-dependent curves were obtained for the inhibition by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and trimetazidine (IC(50) 7 microM and 0.7 microM) of kainate stimulations. After AMPA stimulation, dose-response inhibition curves showed an IC(50) of 3 microM for CNQX and 25 microM for trimetazidine. These results indicate that trimetazidine could be a potent antagonist of AMPA/kainate receptors in vestibular ganglion neurons. This may explain the protective role of trimetazidine in the inner ear suggesting an anti-excitotoxic activity.

Protective Effects of Trimetazidine on Testicular Ischemia-Reperfusion Injury in Rats

INTRODUCTION

We tried to prove the effectiveness of trimetazidine (TMZ) on testicular torsion-detorsion injury.

MATERIALS AND METHODS

15 male rats were equally divided into three groups: group 1 was the sham-operated control group; group 2 had 2 h of unilateral testicular ischemia followed by 3 days of reperfusion, and group 3 had 2 h of unilateral testicular ischemia followed by 3 days of oral TMZ treatment (5 mg/kg, bid) during reperfusion. In the removed testicles, tissue reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), malondialdehyde (MDA) levels and pathological modified Johnson scores (MJS) were evaluated. Mann-Whitney U test was used for statistical evaluations.

RESULTS

In group 2, on the ipsilateral side, GSH were significantly lower and MDA were higher than in groups 1 and 3, though GSH and MDA were not statistically different between groups 1 and 3. On the other hand, GPx in the control testicles of group 3 was significantly lower compared to those in the counterparts of both groups 1 and 2. Among three groups, GR determined in both testicles were not statistically different. On the ipsilateral side, MJS in group 3 were lower than in the sham group, but significantly higher than in group 2.

CONCLUSIONS

According to this study, TMZ has an antioxidant effect on testicular torsion-detorsion injury, though the protective effect of TMZ seems to decrease in control testicles. Consequently it has been considered that TMZ can be only used in torsion patients with a healthy contralateral testicle after further studies have been conducted.

The effects of chronic trimetazidine treatment on mechanical function and fatty acid oxidation in diabetic rat hearts

Clinical and experimental evidence suggest that increased rates of fatty acid oxidation in the myocardium result in impaired contractile function in both normal and diabetic hearts. Glucose utilization is decreased in type 1 diabetes, and fatty acid oxidation dominates for energy production at the expense of an increase in oxygen requirement. The objective of this study was to examine the effect of chronic treatment with trimetazidine (TMZ) on cardiac mechanical function and fatty acid oxidation in streptozocin (STZ)-diabetic rats. Spontaneously beating hearts from male Sprague–Dawley rats were subjected to a 60-minute aerobic perfusion period with a recirculating Krebs–Henseleit solution containing 11 mmol/L glucose, 100 μU/mL insulin, and 0.8 mmol/L palmitate prebound to 3% bovine serum albumin (BSA). Mechanical function of the hearts, as cardiac output × heart rate (in (mL/min)·(beats/min)·10–2), was deteriorated in diabetic (73 ± 4) and TMZ-treated diabetic (61 ± 7) groups compared with control (119 ± 3) and TMZ-treated controls (131 ± 6). TMZ treatment increased coronary flow in TMZ-treated control (23 ± 1 mL/min) hearts compared with untreated controls (18 ± 1 mL/min). The mRNA expression of 3-ketoacyl-CoA thiolase (3-KAT) was increased in diabetic hearts. The inhibitory effect of TMZ on fatty acid oxidation was not detected at 0.8 mmol/L palmitate in the perfusate. Addition of 1 μmol/L TMZ 30 min into the perfusion did not affect fatty acid oxidation rates, cardiac work, or coronary flow. Our results suggest that higher expression of 3-KAT in diabetic rats might require increased concentrations of TMZ for the inhibitory effect on fatty acid oxidation. A detailed kinetic analysis of 3-KAT using different concentrations of fatty acid will determine the fatty acid inhibitory concentration of TMZ in diabetic state where plasma fatty acid levels are increased.

Trimetazidine improves endothelial dysfunction in chronic heart failure: an antioxidant effect

AIMS

To determine whether trimetazidine (TMZ) improves the endothelium-dependent relaxation (EDR) in chronic heart failure (CHF) and whether this effect is associated with its antioxidant properties.

METHODS AND RESULTS

We studied 51 patients (mean age 51.4 +/- 6 years) with CHF secondary to ischaemic cardiomyopathy (ejection fraction 32.5 +/- 4.5%). Plasma malondialdehyde (MDA) and lipid hydroperoxides (LOOHs) were measured from an antecubital vein on study entry and after a 4 week treatment with oral TMZ (20 mg tid) (group T, n = 23) or placebo (group C, n = 22) given randomly. Endothelium-dependent vasodilation of the radial artery (RA) was determined by intra-arterial infusion of acetylcholine (7.5, 15 and 30 microg/min). Patients receiving TMZ had an increased radial artery diameter (RAD) in response to each dose of acetylcholine infusion and a greater peak oxygen uptake (P < 0.01 vs. placebo). Plasma MDA and LOOHs levels were reduced at 4 weeks only in patients receiving TMZ (P < 0.001 for both vs. placebo). The improvement in ED-vasodilation was correlated with changes in peak VO(2) (r = 0.68; P = 0.0001), MDA (r = -0.61; P = 0.0002) and LOOHs (r = -0.59; P = 0.005).

CONCLUSION

TMZ improves the ED-relaxation in patients with ischaemic cardiomyopathy. The antioxidant properties of TMZ may play a role.

Comparison of protective effects of trimetazidine against experimental warm ischemia of different durations: early and long-term effects in a pig kidney model

Acute renal failure (ARF) is often the consequence of an ischemia-reperfusion injury (IRI) and associated with high mortality. Warm ischemia (WI) is a crucial factor of tissue damage, and tissue destruction led by ischemia-reperfusion (I/R) can impact the early and long-term functional outcome. Trimetazidine (TMZ) is an anti-ischemic drug. Previously, we already verified its protective effect on a cold-ischemic pig kidney model by directly adding TMZ into the preservation solution (Faure JP, Baumert H, Han Z, Goujon JM, Favreau F, Dutheil D, Petit I, Barriere M, Tallineau C, Tillement JP, Carretier M, Mauco G, Papadopoulos V, Hauet T. Biochem Pharmacol 66: 2241-2250, 2003; Faure JP, Petit I, Zhang K, Dutheil D, Doucet C, Favreau F, Eugene M, Goujon JM, Tillement JP, Mauco G, Vandewalle A, Hauet T. Am J Transplant 4: 495-504, 2004). In this study, we aimed to study the potential effect of TMZ pretreatment (5 mg/kg iv 24 h before WI) on the injury caused by WI for 45, 60, and 90 min and reperfusion in a WI pig kidney model. Compared with sham-operated (control) and uninephrectomized animals (UNX), TMZ pretreatment significantly reduced deleterious effects after 45 min, and particularly 60 and 90 min, of WI by improving the recovery of renal function and minimizing the inflammatory response commonly prevalent in ischemic kidney injury. Compared with controls (control group and UNX group), it was observed that 1) hypoxia-inducible factor-1 (HIF-1alpha) expression occurred earlier and with a higher intensity in the TMZ-treated groups; 2) the reduction of IRI during the first week following reperfusion was correlated with an earlier and greater expression of stathmin, which is involved in the process of tubular repair; and 3) the tubulointerstitial fibrosis was reduced, particularly after 60 and 90 min of WI. In conclusion, TMZ made the warm-ischemic kidneys more resistant to the deleterious impact of a single episode of I/R and reduced early and long-term subsequent damage.

Protective effect of astragalosides on myocardial injury by isoproterenol in SD rats

We have extracted and roughly purified astragalosides (AS) from Astragalus membranaceus, a natural herb used as a traditional Chinese medicine, regarded to have pharmacodynamic benefits of protecting injured myocardium. We hypothesized that the astragalosides might exert beneficial effect in myocardial lesion by preserving both energy metabolism and Ca(2+) homeostasis. Sprague-Dauley (SD) rats were injected with isoproterenol (ISO) subcutaneous (s.c.) at a dose of 5 mg/kg/day consecutively for two days as models and were treated with astragalosides and trimetazidine intraperitoneally (i.p.) respectively, at a dose of 5 mg/kg/day one day prior to isoproterenol for 8 days. The histological changes were alleviated in isoproterenol-injected SD rats treated with astragalosides. Compared with isoproterenol-injected rats, the concentration of myocardial intracellular [Ca(2+)]i was decreased, L-type Ca(2+) current density and sarcoplasmic reticulum (SR) Ca(2+) load were recovered, the concentration of myocardial ATP was increased and phosphocreatine (PCr) was decreased in rats treated with astragalosides. In conclusion, the efficacious treatment of astragalosides for myocardial injury might be through regulating intracellular Ca(2+) homeostasis and energy metabolism.

Trimetazidine inhibits cardiomyocyte apoptosis in a rabbit model of ischemia-reperfusion

The effects of trimetazidine on cardiomyocyte apoptosis and hemodynamics in a rabbit model of ischemia-reperfusion were determined. Thirty male New Zealand white rabbits were randomly divided into sham, control, and treated groups (n = 10). Trimetazidine (2 mg/kg(-1)/day(-1)) was fed for 2 weeks to treated animals before the procedure. Control and treated groups were subjected to a 30-min coronary occlusion followed by a 2-h reperfusion. Mean arterial pressure, left ventricular systolic pressure, and maximum rate of left ventricular pressure rise were significantly higher in the treated group than in the controls (P < 0.01, < 0.01, and < 0.05, respectively), whereas left ventricular end-diastolic pressure was significantly lower in the treated group than in the controls (P < 0.01). As compared with the sham group, controls had a significantly higher apoptotic index (22.10% +/- 2.85% vs 0.51% +/- 0.31%, P < 0.01) and malondialdehyde (MDA) concentration (18.52 +/- 1.51 vs 5.75 +/- 0.95 micromol/, P < 0.01), and significantly lower serum superoxide dismuase (SOD) levels (66.40 +/- 7.92 vs 89.25 +/- 1.36 microU/L, P < 0.01). Trimetazidine pretreatment apparently decreased apoptotic index (11.37% +/- 2.53%, P < 0.01 vs the sham or control) and MDA concentration (5.49 +/- 0.74 micromol/L, P > 0.05 vs sham, P < 0.01 vs control), and increased SOD levels (88.81 +/- 2.81 microU/L, P > 0.05 vs sham, P < 0.01 vs control). The caspase-3 activation and mitochondrial cytochrome c release were also higher in controls than in the treated group (P < 0.01). The apoptotic indices were negatively correlated with SOD and positively correlated with MDA in the groups, suggesting that trimetazidine may be a useful drug in preventing cardiomyocyte apoptosis and ischemia-reperfusion injury.

Effects of chronic trimetazidine treatment on myocardial preconditioning in anesthetized rats

Trimetazidine is a widely used anti-ischemic agent, but effects of its chronic treatment on myocardial preconditioning in anesthetized animals have not been investigated. The aim of this study was to examine the effects of 15-day treatment of trimetazidine on ischemic preconditioning and carbachol-induced preconditioning in anesthetized rats. Ischemic preconditioning, induced by 5 min of coronary artery occlusion and 5 min of reperfusion, significantly decreased the total number of ventricular ectopic beats, the incidence of ventricular tachycardia and abolished the occurrence of ventricular fibrillation (VF) during 30 min of ischemia. Trimetazidine (10 mg/kg/day, i.p. for 15 days and 10 mg/kg, i.v.) itself attenuated these arrhythmia parameters with no marked effect on hemodynamic effects. In the presence of trimetazidine, anti-arrhythmic effects of ischemic preconditioning were present. Carbachol infusion induced preconditioning with a marked depression of mean arterial blood pressure, heart rate and the total number of ventricular ectopic beats. No VF was observed in carbachol-induced preconditioning. The marked reductions in arrhythmia parameters that induced carbachol-induced preconditioning were also preserved in the presence of trimetazidine. Arrhythmia scores and myocardial infarct size were reduced significantly with ischemic preconditioning or carbachol-induced preconditioning and were not modified by trimetazidine. Lactate and malondialdehyde levels were suppressed significantly with preconditioning or trimetazidine + preconditioning groups. These results show that chronic treatment of trimetazidine protects the heart against ischemia-induced arrhythmias, reduces myocardial infarct size, plasma lactate and malondialdehyde levels, and preserves the effects of ischemic and pharmacological preconditioning in anesthetized rats.

[Derangements of contractility of left ventricular myocardium in patients subjected to coronary bypass surgery. Methods of their correction]

Coronary bypass grafting with the use of cardiopulmonary bypass was performed in 119 patients (age 41-75 years) with stable angina. In addition to standard therapy in pre and post operative periods patients of group 1 (n=40) received mildronate (750 mg/day for 3 days then 750 mg twice weekly), patients of group 2 (n=41) received trimetazidine (70 mg/day). Patients of group 3 (n=38) received no "metabolic" drugs. The use of cardioprotectors mildronate and trimetazidine facilitated improvement of total and local myocardial contractility both before and after surgery, and caused limitation of development of myocardial stunning, associated with derangement of local contractility in post operative period.

Trimetazidine administration minimizes myocardial damage and improves left ventricular function after percutaneous coronary intervention

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate whether the administration of trimetazidine, a piperazine derivative, to patients before and after percutaneous coronary intervention (PCI) minimizes the PCI-induced myocardial damage and improves left ventricular function 1 and 3 months after the procedure.

METHODS

Fifty-two patients hospitalized for acute coronary syndromes (ACS) were included in this study. Patients were randomized into two groups: group A (trimetazidine group; n = 27) and group B (placebo group; n = 25). All patients received conventional antianginal therapy. In addition, group A patients received oral trimetazidine 20 mg every 8 hours, starting 15 days before PCI and continuing for 3 months after the procedure. For each patient, serum troponin I and creatinine kinase (CK)-MB levels were measured before PCI, then at 6, 24, and 48 hours after the procedure; a 2D cardiac echocardiogram was performed before PCI and at 1 and 3 months after the procedure.

RESULTS

Twenty-four hours after PCI, troponin I levels were >1 ng/mL in 7 of 27 patients (26%) of group A and 11 of 25 patients (44%) in group B. Fourty-eight hours after revascularization troponin levels remained elevated in 15% of patients in group A and in 32% of patients in group B. Twenty-two percent of patients in group A had CK-MB levels >5 ng/mL, 24 hours after PCI, compared with 40% of patients in group B; four patients of group A had high CK-MB levels prior to PCI procedure. Echocardiographic measurements before revascularization revealed that 11 of 27 patients (40%) in group A had an ejection fraction <50% versus 8 of 24 patients (33%) in group B . The number of patients with an ejection fraction <50% was significantly reduced in group A compared with group B at 1 and 3 months after PCI, i.e. 11% versus 16% (p = 0.046) at 1 month and 4% versus 16% (p = 0.017) at 3 months.A significant improvement in regional wall motion was noted after treatment with trimetazidine compared with placebo. One month after PCI, inferior left ventricular (LV) wall hypokinesia had improved in 4 of 6 trimetazidine recipients and in 4 of 14 placebo recipients (p = 0.014, group A vs group B). After 3 months inferior wall hypokinesia improved in four patients in group A versus six patients in group (p = 0.05). Similarly, anterior LV wall motion improved in 3 of 11 patients in group A and in 1 of 6 patients in group B at 1 month. After 3 months anterior wall hypokinesia had improved in eight patients in group A and in two patients in group B (p = 0.04, group A vs group B).

CONCLUSION

The metabolic agent trimetazidine appears to minimize myocardial reperfusion injury during PCI and improves global and regional wall motion at 1 and 3 months after PCI. This study was limited by small patient numbers and further studies are necessary to evaluate exact mechanisms of action and clinical implications of using trimetazidine in conjunction with PCI.

Trimetazidine-induced enhancement of myocardial recovery during reperfusion: a comparative study in diabetic and non-diabetic rat hearts

BACKGROUND

Diabetes mellitus (DM) is a major predisposing factor for ischemic heart disease. Metabolic disturbances in diabetic heart including impaired myocardial glucose uptake and elevated plasma free fatty acids and increased rate of fatty acid beta-oxidation are probably important contributing factors to greater mortality. Trimetazidine (TMZ), a well-studied anti-ischemic agent, has been demonstrated to be beneficial in treatment of coronary artery disease as well as in treatment of diabetic patients. However, studies reporting the effects of the drug against global myocardial ischemia/reperfusion injury, particularly in diabetic hearts, are rare. This study was mainly aimed to investigate the cardioprotective action of TMZ against global ischemia in diabetic hearts and to compare its protective efficiency level with non-diabetics.

METHODS

Twenty streptozotocin-induced diabetic and 20 non-diabetic rats were divided into two groups each. Group I (diabetic, n = 10) and group III (non-diabetic, n = 10) rats were given saline in both pretreatment and acute treatment protocols and reserved as control groups. Group II (diabetic, n = 10) and group IV (non-diabetic, n = 10) rats were both pretreated orally with 3 mg/kg TMZ twice daily for 5 days and treated with TMZ infusion at a concentration of 10(-6) M for 30 min during the experiment. Isolated hearts from each rat were submitted to Langendorff perfusion and a period of 60 min of global ischemia following 60 min of reperfusion. Myocardial post-ischemic recovery was compared in each group using hemodynamic data (peak systolic pressure, end diastolic pressure, +dP/dt(max)), coronary flow, biochemical parameters (CK-MB, cTnT) from coronary effluent, and obtained data were statistically analyzed by both MANOVA and two-sample Hotelling's T2 tests.

RESULTS

Both hemodynamic and biochemical findings signaled a significantly enhanced myocardial recovery provided by TMZ treatment in diabetic and non-diabetic hearts as compared to non-treated hearts. Although efficiency level of TMZ on mechanical recovery was not different between diabetics and non-diabetics, the protective action of TMZ on myocardial damage measured by biochemical parameters was more evident in diabetic hearts than in non-diabetics.

CONCLUSIONS

Shifting myocardial energy metabolism away from fatty acids toward glucose oxidation and regulating transmembrane ion disturbances by TMZ can be considered as an appropriate adjunctive treatment in diabetics, especially in patients undergoing open-heart surgery who will be exposed to global myocardial ischemia.

Silent myocardial ischaemia: clinical relevance and treatment

Transient myocardial ischaemia in the absence of chest pain ('silent ischaemia') commonly occurs in patients with coronary artery disease (CAD) and has important prognostic implications. However, doubts exist as to whether and how silent ischaemia should be managed. In the present article we review current knowledge regarding silent ischaemia and the role of recently developed drugs that may be effective to control its occurrence. Since the description in the 1770s of the syndrome of 'angina pectoris' by William Heberden, the importance of chest pain for the diagnosis of CAD has remained un-abated. However, several decades ago it became apparent that both myocardial infarctions and transient episodes of myocardial ischaemia could occur in the absence of chest pain. Indeed, a large proportion of patients with CAD have both silent and painful myocardial ischaemia as a manifestation of CAD. Whether the presence of asymptomatic ischaemic electrocardiographic changes in patients with CAD has prognostic importance and whether it needs medical or surgical treatment has been a matter of speculation for several decades.

Chronic treatment with trimetazidine reduces the upregulation of atrial natriuretic peptide in heart failure

Trimetazidine (TMZ) is effective for the treatment of ischemic cardiomyopathy; however, little is known about the effect of TMZ in established injury-induced heart failure. When rats with established infarct-induced heart failure were treated for 12 weeks with TMZ there was no effect on left ventricular function or dilation, or on mRNA expression of fatty acid oxidation enzymes. On the other hand, TMZ significantly reduced atrial natriuretic peptide mRNA levels compared with untreated rats.

Trimetazidine increases [3H]glucose uptake in rat brain

Trimetazidine, a clinically effective antianginal agent with no negative inotropic or vascular properties, acts by optimizing cardiac energy metabolism through inhibition of free fatty acid oxidation, shifting substrate utilization from fatty acids to glucose. Up to now there has been no study associating trimetazidine's effect on metabolic processes with glucose utilization in the mammalian brain. The objective of the present study was to determine if trimetazidine altered [(3)H]glucose uptake in rat brain. Adult male Wistar rats were administered trimetazidine (Metazydyna, Polfa) either as a single dose (10.0 mg/kg po) or for 14 consecutive days (5.0 mg/kg po per day) or vehicle saline (2.0 ml/kg po). Sixty minutes after the single dose or 14th dose of trimetazidine, and 15 min before experiment termination and brain dissection, 6-[(3)H]D-glucose (500 Ci/kg ip; Amersham) was administered. Using liquid scintillation counting, trimetazidine, either in a single or multiple dose regimen, was found to increase [(3)H]glucose uptake (DPM/100 mg of wet tissue) in all dissected regions of the brain (i.e., striatum, hippocampus, frontal cortex, thalamus with hypothalamus, pons with medulla oblongata, and cerebellum). Therefore, central effects need to be taken into consideration as possibly adding to known beneficial cardiac effects of trimetazidine.

The anti-anginal drug trimetazidine reduces neutrophil-mediated cardiac reperfusion injury

Trimetazidine has no hemodynamic/antithrombotic actions. Hence, its anti-ischemic properties have been mostly attributed to its metabolic effects. However, this issue is not completely elucidated. We investigated whether inhibition of neutrophil activation may also contribute to its cardioprotective action. We first showed that trimetazidine inhibits neutrophil activation in vitro. We subsequently tested whether trimetazidine protects postischemic hearts from neutrophil-mediated injury. Four groups of rat hearts underwent 20 minutes of global ischemia: (1) controls, reperfused with neutrophil-enriched buffer for 5 minutes, followed by 40 minutes standard perfusate; (2) hearts from rats pretreated with trimetazidine for 1 week; (3) hearts in which 10 M trimetazidine was added to the perfusate, starting 5 minutes before ischemia and for the initial 15 minutes of reflow; (4) hearts from pretreated rats that also received trimetazidine in the perfusate. Postischemic impairment of contractile function was significantly attenuated by trimetazidine infusion (recovery of developed pressure: 68 +/- 7% versus 42 +/- 9% of baseline in controls; P < 0.05). Pretreatment alone was not effective, nor did it further improve the beneficial effects of infusion. Cardiac oxygen radical production at reflow (by electron paramagnetic resonance spectroscopy) was also reduced by trimetazidine, independently of direct scavenger effects. Thus, trimetazidine can protect postischemic hearts from neutrophil-mediated injury.

Structure-activity studies on the protection of Trimetazidine derivatives modified with nitroxides and their precursors from myocardial ischemia-reperfusion injury

Trimetazidine, the known anti-anginal and anti-ischemic drug, was modified by pyrroline and tetrahydropyridine nitroxides and their hydroxylamine and sterically hindered secondary amine precursors. The synthesized new compounds proved to be better superoxide scavenger molecules compared to the parent Trimetazidine in an in vitro experiment. This reactive oxygen species (ROS) scavenging activity was further supported by ischemia/reperfusion (I/R) studies on Langendorff-perfused rat hearts pretreated with Trimetazidine and with the modified Trimetazidine derivatives before ischemia. Two of the investigated compounds, containing 2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole and 4-phenyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole substituents on the piperazine ring, provided significant protection from the cardiac dysfunction caused by I/R. The protective effect could be attributed to the combined anti-ischemic and antioxidant effects.

Cardiac mitochondrial alterations induced by insulin deficiency and hyperinsulinaemia in rats: targeting membrane homeostasis with trimetazidine

The present study investigated the ability of trimetazidine (TMZ) to maintain cardiac mitochondrial function during the development of insulin deficiency and hyperinsulinaemia. The anti-ischaemic drug TMZ is known to increase phospholipid synthesis in cardiac membranes and to have a cardioprotective effect. Insulin deficiency was obtained by streptozotocin injection and hyperinsulinaemia was achieved via a fructose diet. Trimetazidine was incorporated into the diet (7.8 mg/day) and mitochondrial function was evaluated in skinned cardiac fibres. Insulin deficiency decreased mitochondrial affinity for ADP and the index of creatine kinase functional activity. This last alteration was partially prevented by TMZ treatment. Insulin deficiency strongly decreased n-3 polyunsaturated fatty acids, especially the docosahexaenoic acid (DHA) content, in cardiac and mitochondrial membranes, inducing a strong increase in the n-6/n-3 ratio. Trimetazidine treatment limited the increase in the n-6/n-3 ratio and prevented the decrease in DHA content in mitochondrial membranes. Insulin deficiency decreased glutamate- and palmitoylcarnitine-supported respiration. Hyperinsulinaemia affected neither mitochondrial affinity for ADP nor the index of creatine kinase functional activity. Hyperinsulinaemia slightly and significantly affected mitochondrial fatty acid composition, by a small increase the n-6/n-3 ratio. Trimetazidine did not modify membrane-bound mitochondrial function but increased the n-6/n-3 ratio. Moreover, hyperinsulinaemia decreased glutamate-supported respiration. In conclusion, modification of membrane homeostasis with TMZ partially prevented the alterations in fatty acid composition and function in cardiac mitochondria induced by insulin deficiency. Three months of hyperinsulinaemia did not modify membrane-bound mitochondrial function and had only slight effects on fatty acid composition.

Attenuation of myocardial ischemia-reperfusion injury by trimetazidine derivatives functionalized with antioxidant properties

Trimetazidine (TMZ), an anti-ischemic metabolic drug, is used to treat chest pain (angina pectoris). We hypothesized that derivatives of TMZ with antioxidant functions may improve the cardiac dysfunction caused by ischemia-reperfusion (I/R) above that observed with TMZ alone. Isolated rat hearts perfused with Krebs-Henseleit buffer according to the Langendorff method were subjected to 30 min of global ischemia followed by 45 min of reperfusion. Trimetazidine, TMZ-NH (TMZ modified with a pyrroline moiety), or TMZ-PhiNH (TMZ-NH with a phenyl substitute) were infused (50 microM) for 1 min before the onset of ischemia. Untreated (control) hearts at the end of 45 min of reperfusion showed a significant decrease in the recovery of coronary flow (42%), left ventricular-developed pressure (22%), and rate-pressure product (25%) compared with preischemic baseline values. The I/R hearts also showed markedly increased lactate dehydrogenase and creatine kinase activities in the coronary effluent, significant myocardial infarction (46% of risk area), and activation of Akt, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase. Pretreatment of hearts with TMZ-NH or TMZ-PhiNH significantly enhanced the recovery of heart function and decreased infarct size. The I/R-induced activation of Akt was further enhanced by TMZ-PhiNH. The present study demonstrated that TMZ-NH and TMZ-PhiNH significantly protected hearts against I/R-mediated cardiac dysfunction and injury. The protective effect of the TMZ derivatives could be due to the combined effects of antioxidant and anti-ischemic activities as well as enhanced pro-survival Akt activity.

Effect of trimetazidine on the nucleotide profile in rat kidney with ischemia-reperfusion injury

Ischemia-reperfusion injury is often responsible for delayed graft function after transplantation. Trimetazidine (TMZ) is an antioxidant agent used to protect grafts from ischemia-reperfusion injury. The aim of the study was to examine the effect of TMZ on nucleotide profile in rat kidney with ischemia-reperfusion injury. The study was carried out on Wistar rats divided into two groups: animals treated with TMZ and control group receiving placebo. TMZ 10mg/kg/day was administrated for 30 days. Concentrations of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), adenosine (Ado), guanosine triphosphate (GTP), guanosine diphosphate (GDP), guanosine monophosphate (GMP), guanosine (Guo), inosine monophosphate (IMP), inosine (Ino), hypoxanthine (Hyp), xanthine (Xan), uric acid (UA), uridine (Urd), nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) were determined in kidney tissues after ischemia-reperfusion using HPLC. The total adenine nucleotide concentration (TAN) and adenylate energy charge (AEC) were also determined. Moreover the kidneys were evaluated histologically. Tissue concentrations of ATP, ADP, AMP, TAN and AEC were significantly increased in kidneys from rats treated with TMZ in comparison with rats receiving placebo. Concentrations of products of nucleotide degradation: inosine (Ino), guanosine (Guo) and uridine (Urd), as well as oxypurines: Hyp and Xan, were significantly decreased in rats treated with trimetazidine. Moreover, significantly less pronounced acute tubular necrosis was observed in kidneys of rats treated with TMZ. These results suggest that trimetazidine protects against dephosphorylation of nucleotides and ischemic damage.

Metabolic and endothelial effects of trimetazidine on forearm skeletal muscle in patients with type 2 diabetes and ischemic cardiomyopathy

The aim of the present study was to evaluate the effect of prolonged inhibition of beta-oxidation on glucose and lipid muscle forearm metabolism and cGMP and endothelin-1 forearm release in patients with type 2 diabetes mellitus and ischemic cardiomyopathy. Fifteen patients were randomly allocated in a double-blind cross-over parallel study with trimetazidine (20 mg tid) or placebo lasting 15 days. At the end of each period, all patients underwent euglycemic hyperinsulinemic clamps with forearm indirect calorimetry and endothelial balance of vasodilator and vasoconstricor factors. Compared with placebo, trimetazidine induced 1) an increase in insulin-induced forearm glucose uptake and glucose oxidation accompanied by a reduction in forearm lipid oxidation and citrate release and 2) a decrease of endothelin-1 release paralleled by a significant increase in forearm cGMP release. Forearm glucose oxidation significantly correlated with cGMP release (r=0.37, P<0.04), whereas forearm lipid oxidation positively correlated with endothelin-1 release (r=0.40, P<0.03). In conclusion, for the first time, we demonstrated that insulin-induced forearm glucose oxidation and forearm cGMP release were increased whereas forearm endothelin-1 release was decreased during trimetazidine treatment. Muscle's metabolic and vascular effects of trimetazidine add new interest in the use of trimetazidine in type 2 diabetic patients with cardiovascular disease.

[The effects of trimetazidine on left ventricular function and physical exercise tolerance in patients with ischemic cardiomyopathy]

Trimetazidine is a new metabolic antiischemic agent, which increases the tolerance of cardiomyocytes to ischemia. The aim of the study was to evaluate the effect of additional trimatazidine therapy in patients with ischemic cardiomyopathy (ICMP) in comparison with standard therapy of cardiac insufficiency. According to the results of the study, trimetazidine improves the clinical status, functional class of cardiac insufficiency, left ventricular ejection fraction, in ICMP patients. Trimetazidine increases physical exercise tolerance according to the results of six-minute walking test. Thus, the optimization of myocardial energetic metabolism may be a promising perspective in the treatment of coronary heart disease with systolic dysfunction.

Pharmacological investigation of trimetazidine in models of inflammation, pain and gastric injury in rodents

The antinociceptive, anti-inflammatory and gastric effects of trimetazidine (2,3,4-trimethoxybenzyl-piperazine dihydrochloride), a novel anti-ischaemic compound, were evaluated in various animal models. In acute pain models, namely acetic acid-induced writhing, hot-plate assay, tail electric stimulation test, capsaicin-induced pain and the formalin test, trimetazidine (1.8-7.2 mg/kg, i.p.) showed marked antinociceptive effects. Trimetazidine did not produce any behavioural impairment as revealed by the mouse rotarod. The inhibition of writhing response by trimetazidine was reduced by yohimbine, theophylline (and to a certain extent by sulpiride) but not by prazosin, guanethidine, naloxone, atropine, propranolol, haloperidol, domperidone, clozapine, glibenclamide or caffeine. The carrageenan-evoked acute paw oedema was reduced by 19.2-21.2 and 17-18.6% by 3.6 and 7.2 mg/kg trimetazidine, respectively. The drug did not alter the oedema-suppressive effect of indomethacin or dexamethasone, but reduced that of rofecoxib. Trimetazidine at 7.2 mg/kg reduced immobility time in Porsolt's forced-swimming test by 28.9%. The acute gastric mucosal lesions evoked by indomethacin in the rat were inhibited in a dose-dependent manner by co-administration of trimetazidine. In anesthetized rats, trimetazidine potentiated the gastric acid secretory response. This study indicates that trimetazidine possesses antinociceptive and gastric protective properties. The antinociceptive properties of trimetazidine are likely to be centrally mediated, but do not involve opioid pathways.

Mitochondrial changes induced by trimetazidine in the myocardium

BACKGROUND

The aim was to assess the effect of trimetazidine (TMZ) on mitochondrial alterations induced in a canine model of brief, repeated episodes of ischemia.

MATERIAL/METHODS

Twelve crossbred dogs were analyzed, after double-blind randomization, to a 7-day treatment with either TMZ or placebo. Twenty brief, complete occlusions of the left anterior descending coronary artery were performed. Mitochondrial analysis entailed a qualitative (percentage of mitochondrial damage, merging, pairing, vacuoles, and lipofucsin granules) and a quantitative size analysis (major and minor axes, perimeter, and area) of the mitochondria in the ischemic and control zones.

RESULTS

Comparative study of the control zones revealed an increase in lipofucsin granules in the TMZ series and a greater percentage of damaged mitochondria and vacuoles. The control-zone mitochondria treated with TMZ presented a significant increase in the perimeter and major axis and a decrease in the minor axis (p<0.005). No significant differences were found between the series in the qualitative analysis of mitochondrial damage in the ischemic zone. The mitochondria in the TMZ series presented a greater major axis and perimeter than those in the placebo series (p<0.05), which presented a smaller minor axis.

CONCLUSIONS

TMZ made the mitochondria adopt an elongated, "rod-like" morphology in both the control and ischemic zones. This is interpreted as an increase in the membrane surface. In the non-ischemic zone, TMZ produced an increase in mitochondrial turnover. There were no differences in the myocardium subjected to ischemia in both series in terms of observable mitochondrial damage.

Protective effect of trimetazidine on myocardial mitochondrial function in an ex-vivo model of global myocardial ischemia

Trimetazidine is an anti-ischemic drug whose cytoprotective mechanisms are not yet fully understood (but until now mainly related to the trimetazidine-induced "metabolic shift" from lipid beta-oxidation to glucose aerobic oxidation). We studied the effect of trimetazidine on the mitochondrial function of ischemic Wistar rat hearts perfused with glucose, using a model of ex-vivo perfusion (Langendorff system). We measured the electrical potential of the mitochondrial membrane, O2 consumption by the respiratory chain, energy charges generated and the enzyme activities of the respiratory chain complexes. In this model, trimetazidine had a preferential action on the oxidative system (mainly on complex I), increasing its enzyme activity and decreasing O2 consumption after phosphorylation; this could decrease oxygen free radical production and increase mitochondrial integrity, thus allowing the maintenance of the electrical potential. These results allow us to better understand the cytoprotective effects of trimetazidine in coronary artery disease.

Effects of trimetazidine on myocardial preconditioning in anesthetized rats

Trimetazidine is a widely used anti-ischemic agent, but its effect on myocardial preconditioning in anesthetized animals has not been investigated. The aim of this study was to examine the effects of trimetazidine on ischemic preconditioning and carbachol preconditioning in anesthetized rats. Ischemic preconditioning, induced by 5-min coronary artery occlusion and 5-min reperfusion, decreased the incidence of ventricular tachycardia and abolished the occurrence of ventricular fibrillation during 30-min ischemia. Trimetazidine (10 mg/kg, i.v.) alone attenuated these parameters of arrhythmia. Carbachol infusion induced preconditioning with a marked depression of mean arterial blood pressure, heart rate and ventricular tachycardia. The marked reductions in parameters of arrhythmia induced by ischemic preconditioning and carbachol preconditioning were preserved in the presence of trimetazidine. Arrhythmia scores and myocardial infarct size were significantly reduced with ischemic preconditioning or carbachol preconditioning and were not inhibited by trimetazidine. These results show that trimetazidine protects the heart against ischemia-induced arrhythmias, reduces myocardial infarct size, preserves the effects of ischemic preconditioning and pharmacological preconditioning, and is able to mimic ischemic preconditioning in anesthetized rats.