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Background. Cardiovascular disease (CVD) contributes critically to the mortality, morbidity, and economic problem of illness globally. Exercise is a share of everyone's life. Some evidence-based studies have frequently shown a progressive correlation between physical activity and good health. Objective. The effects of daily exercise on cardiomyocyte size, collagen content (fibrosis), and releasing mast cells (MCsʼ) tryptase of the model of myocardial infarction (MI) were assessed. Methods. 40 rats were coincidentally spread into sham+inertia (control), sham+exercise, infarction+inertia, and infarction+exercise groups. An experimental model of acute MI was induced in infarction groups. One week after surgery, exercising groups were allowed to an aerobic exercise program for six weeks. At the endpoint of the study, all examinations were performed. Results. We found lesser fibrosis in sham+exercise and infarction+exercise groups compared to sham+inertia and infarction+inertia groups, respectively (p = 0.023 , p = 0.001). Also, infarction groups were significantly lower than sham groups (p < 0.05) and the infarction+exercise group was significantly lower than the infarction+inertia group (p < 0.05). The effect of exercise on MCs while increased MC density and degranulation occur at the site of fibrosis, we demonstrated that exercise decreases both total MC density and degranulation in both sham and infarction groups (p < 0.05). Immunohistochemistry examinations were significantly higher expression of MCsʼ tryptase in infarction groups than sham groups (p < 0.05 , p < 0.0001). Conclusion. Exercise improves fibrosis and cardiac function in both healthy and MI rats by inhibiting released MCsʼ tryptase. [ABSTRACT FROM AUTHOR]

Persistent cardiovascular pathology has been described in hyperthyroid patients even with effective antithyroid treatment. Here, we studied the effect of a well-known antithyroid drug, propylthiouracil (PTU; 20 mg/kg/day), on thyroxine (T4; 500 µg/kg/day)-induced increase in blood pressure (BP), cardiac hypertrophy, and altered responses of the contractile myocardium both in vivo and ex vivo after 2 weeks of treatment. Furthermore, the potential recovery through 2 weeks of T4 treatment discontinuation was also investigated. PTU and T4 recovery partially reduced the T4-prompted increase in BP. Alternatively, PTU significantly improved the in vivo left ventricular (LV) function with no considerable effects on cardiac hypertrophy or ex vivo right ventricular (RV) contractile alterations subsequent to T4 treatment. Conversely, T4 recovery considerably enhanced the T4-provoked cardiac changes both in vivo and ex vivo. Altogether, our data is in agreement with the proposal that hyperthyroidism-induced cardiovascular pathology could persevere even with antithyroid treatments, such as PTU. However, this cannot be generalized and further investigation with different antithyroid treatments should be executed. Moreover, we reveal that recovery following experimental hyperthyroidism could potentially ameliorate cardiac function and decrease the risk for additional cardiac complications, yet, this appears to be model-dependent and should be cautiously construed. [ABSTRACT FROM AUTHOR]

Diabetic cardiomyopathy (DCM) is an important cause of heart failure in diabetic patients. The present study sought to explore the potential effects of dihydromyricetin (DHM) on DCM and its possible mechanism. A diabetic model was induced by intraperitoneal injection of streptozotocin (STZ) in C57BL/6J mice. Two weeks after the STZ injection, mice were randomly allocated into the following 4 groups for treatment: the control group (CON), the control treated with DHM group (CON + DHM), the diabetes group (DM), and the diabetes treated with DHM group (DM + DHM). DHM was dissolved in distilled water and administered daily by gavage. For 14 weeks, the CON + DHM group and DM + DHM group were given a dose of 100 mg/kg/day DHM (Sigma-Aldrich), while the CON and DM groups were intragastrically given equivalent volumes of distilled water. Assessments and comparisons were made among the groups based on cardiac function and structural changes, inflammation factors, markers of oxidative stress, mitochondria function, apoptosis, and autophagy. The DHM treatment normalized body weight, preserved cardiac function, attenuated oxidative stress (MDA, SOD, and GSH-Px), reduced the levels of inflammation factors (IL-6, TNF-α), alleviated pathological changes, improved mitochondrial function (ATP content, CS activity, and complex Ι/ΙΙ/ΙΙΙ/ΙV/V activities), inhibited cardiac apoptosis, and restored autophagy in diabetic mice. DHM may have a great therapeutic potential in the treatment of DCM. [ABSTRACT FROM AUTHOR]

Among other diseases characterized by the onset of cachexia, congestive heart failure takes a place of relevance, considering the high prevalence of this pathology in most European countries and in the United States, and is undergoing a rapid increase in developing countries. Actually, only few models of cardiac cachexia exist. Difficulties in the recruitment and follow-up of clinical trials implicate that new reproducible and well-characterized animal models are pivotal in developing therapeutic strategies for cachexia. We generated a new model of cardiac cachexia: a transgenic mouse expressing Tpr-Met receptor, the activated form of c-Met receptor of hepatocyte growth factor, specifically in the heart. We showed that the cardiac-specific induction of Tpr-Met raises a cardiac hypertrophic remodelling, which progresses into concentric hypertrophy with concomitant increase in Gdf15 mRNA levels. Hypertrophy progresses to congestive heart failure with preserved ejection fraction, characterized by reduced body weight gain and food intake and skeletal muscle wasting. Prevention trial by suppressing Tpr-Met showed that loss of body weight could be prevented. Skeletal muscle wasting was also associated with altered gene expression profiling. We propose transgenic Tpr-Met mice as a new model of cardiac cachexia, which will constitute a powerful tool to understand such complex pathology and test new drugs/approaches at the preclinical level. [ABSTRACT FROM AUTHOR]

Objectives. We investigated whether amlodipine could improve angiogenic responses in a diabetic rat model of acute myocardial infarction (AMI) through improving bone marrow endothelial progenitor cell (EPC) mobilization, in the same way as angiotensin converting enzyme inhibitors. Methods. After induction of AMI by coronary artery ligation, diabetic rats were randomly assigned to receive perindopril (2 mgkg−1 day−1), amlodipine (2.5 mgkg−1 day−1), or vehicle by gavage (n=20 per group). Circulating EPC counts before ligation and on days 1, 3, 5, 7, 14, and 28 after AMI were measured in each group. Microvessel density, cardiac function, and cardiac remodeling were assessed 4 weeks after treatment. The signaling pathway related to EPC mobilization was also measured. Results. Circulating EPC count in amlodipine- and perindopril-treated rats peaked at day 7, to an obvious higher level than the control group peak which was reached earlier (at day 5). Rats treated with amlodipine showed improved postischemia neovascularization and cardiac function, together with reduced cardiac remodeling, decreased interstitial fibrosis, and cardiomyocyte apoptosis. Amlodipine treatment also increased cardiac SDF-1/CXCR4 expression and gave rise to activation of VEGF/Akt/eNOS signaling in bone marrow. Conclusions. Amlodipine promotes neovascularization by improving EPC mobilization from bone marrow in diabetic rats after AMI, and activation of VEGF/Akt/eNOS signaling may in part contribute to this. [ABSTRACT FROM AUTHOR]

Oncostatin M (OSM) has been reported to stimulate angiogenesis by upregulating VEGF and bFGF, implying that it could be a therapeutic strategy in treating ischemic diseases. The present study was aimed at investigating whether OSM could improve cardiac function via prompting angiogenesis following myocardial infarction (MI). Wild type (WT) and Oβ knock-out (Oβ−/−) mice were, respectively, randomized into sham group, MI + vehicle group, and MI + OSM group. WT mice displayed significantly impaired cardiac function after MI. OSM treatment attenuated cardiac dysfunction in WT MI mice, while Oβ deletion abrogated the protective effects. Besides, OSM attenuated heart hypertrophy and pulmonary congestion evidenced by decreased heart weight/body weight and lung weight/body weight ratio. Further, reduction of apoptosis and fibrosis in infarct border zone was observed in OSM treated WT MI mice compared with vehicle. Moreover, in WT mice subjected to MI, OSM treatment significantly increased capillary density along with upregulation of p-Akt and angiogenic factors VEGF and bFGF in comparison with vehicle, and this phenomenon was not found in Oβ−/− mice. In conclusion, OSM treatment preserved cardiac function, inhibited apoptosis and fibrosis, and stimulated angiogenesis via upregulating VEGF and bFGF in infarct border zone of ischemic myocardium, indicating that OSM could be a novel therapeutic target for MI. [ABSTRACT FROM AUTHOR]

Background. Apoptosis plays vital roles in the progression of doxorubicin-induced cardiomyopathy (DOX-CM). Endoplasmic reticulum stress (ER stress) could induce specific apoptosis by caspase-12 dependent pathway. Shengmai Injection (SMI), a famous Traditional Chinese Medicine, could alleviate the heart damage via inhibiting myocardial apoptosis. However, it is unknown whether SMI can alleviate ER stress and its specific apoptosis in the setting of DOX-CM. Objective. To explore the effects of SMI on heart function, myocardial ER stress, and apoptosis of DOX-CM rats. Methods. Rats with DOX-CM were treated by SMI. Heart function was assessed by echocardiography and brain natriuretic peptide. Myocardial apoptosis was detected by TUNEL assay. ER stress was assessed by detecting the expressions of GRP78 and caspase-12. Results. At the end of eight-week, compared to control, significant heart dysfunction happened in DOX group. The ratio of apoptotic cardiomyocytes and the expressions of GRP78 and caspase-12 increased significantly (P<0.05). Compared to DOX group, the apoptotic ratio and the expressions of GRP78 and caspase-12 significantly decreased in DOX + SMI group (P<0.05), accompanied with improved heart function. Conclusion. SMI could alleviate myocardial ER stress and caspase-12 dependent apoptosis, which subsequently helped to improve the heart function of rats with DOX-CM. [ABSTRACT FROM AUTHOR]

Background. Novel therapies need to be evaluated in a relevant large animal model that mimics the clinical course and treatment in a reasonable time frame. To reliably assess therapeutic efficacy, knowledge regarding the translational model and the course of disease is needed. Methods. Landrace pigs were subjected to a transient occlusion of the proximal left circumflex artery (LCx) (n=6) or mid-left anterior descending artery (LAD) (n=6) for 150 min. Cardiac function was evaluated before by 2D echocardiography or 3D echocardiography and pressure-volume loop analysis. At 12 weeks of follow-up the heart was excised for histological analysis and infarct size calculations. Results. Directly following AMI, LVEF was severely reduced compared to baseline in the LAD group -17.1±1.6%, P=0.009 compared to only a moderate reduction in the LCx group -5.9±1.5%, P=0.02 and this effect remained unchanged during 12 weeks of follow-up. Conclusion. Two models of chronic MI, representative for different patient groups, can reproducibly be created through clinically relevant ischemia-reperfusion of the mid-LAD and proximal LCx. [ABSTRACT FROM AUTHOR]

Objective. The serotonin (5-HT) pathway was shown to play a role in pulmonary hypertension (PH), but its functions in right ventricular failure (RVF) remain poorly understood. The aim of the current study was to investigate the effects of Terguride (5-HT2A and 2B receptor antagonist) or SB204741 (5-HT2B receptor antagonist) on right heart function and structure upon pulmonary artery banding (PAB) in mice. Methods. Seven days after PAB, mice were treated for 14 days with Terguride (0.2 mg/kg bid) or SB204741 (5 mg/kg day). Right heart function and remodeling were assessed by right heart catheterization, magnetic resonance imaging (MRI), and histomorphometric methods. Total secreted collagen content was determined in mouse cardiac fibroblasts isolated from RV tissues. Results. Chronic treatment with Terguride or SB204741 reduced right ventricular fibrosis and showed improved heart function in mice after PAB. Moreover, 5-HT2B receptor antagonists diminished TGF-beta1 induced collagen synthesis of RV cardiac fibroblasts in vitro. Conclusion. 5-HT2B receptor antagonists reduce collagen deposition, thereby inhibiting right ventricular fibrosis. Chronic treatment prevented the development and progression of pressure overload-induced RVF in mice. Thus, 5-HT2B receptor antagonists represent a valuable novel therapeutic approach for RVF. [ABSTRACT FROM AUTHOR]