RESUMEN

Ten new B-ring aromatized 6/6/6-tricyclic dearomatized benzocogeijerene-based meroterpenoids with unusual methyl 1,2-shift or demethylation (2-9b), and two new geranylquinol derivatives (1 and 10), together with two known compounds (11 and 12), were isolated from the roots of Arnebia euchroma. Their structures were elucidated by extensive spectroscopic methods, X-ray diffraction crystallography, and ECD calculations. The plausible biosynthetic pathways including the unusual methyl 1,2-shfit and demethylation for B-ring aromatized 6/6/6-tricyclic meroterpenoids were discussed. Compounds 1, 2, 5, 6, 11, and 12 showed significant cardioprotective activities comparable to diltiazem against isoprenaline (ISO)-induced H9C2 cell damage in vitro. Compound 11 probably exerted heart-protective effect on ISO-induced H9C2 cells by modulating the PI3K-AKT-mTOR pathway, reducing excessive autophagy, and decreasing myocardial apoptosis.

Asunto(s)

Apoptosis , Autofagia , Boraginaceae , Miocitos Cardíacos , Terpenos , Apoptosis/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Autofagia/efectos de los fármacos , Boraginaceae/química , Ratas , Terpenos/farmacología , Terpenos/química , Terpenos/aislamiento & purificación , Animales , Estructura Molecular , Relación Estructura-Actividad , Relación Dosis-Respuesta a Droga , Insuficiencia Cardíaca/tratamiento farmacológico , Cardiotónicos/farmacología , Cardiotónicos/química , Cardiotónicos/aislamiento & purificación , Línea Celular

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Background: There have been conflicting reports about the proarrhythmic risk of p-synephrine (SYN). To address this, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) combined with the microelectrode array (MEA) system have been utilized to assess arrhythmia risks, particularly in the context of adrenomimetic drugs. Aim: This study aims to determine whether MEA recordings from hiPSC-CMs could predict the proarrhythmic risk of adrenomimetic drugs and to investigate the cardiovascular effects and mechanisms of SYN. Materials and methods: We employed MEA recordings to assess the electrophysiological properties of hiPSC-CMs and conducted concentration-response analyses to evaluate the effects of SYN and Isoprenaline (ISO) on beating rate and contractility. A risk scoring system for proarrhythmic risks was established based on hiPSC-CMs in this study. ISO, a classic beta-adrenergic drug, was also evaluated. Furthermore, the study evaluated the risk of SYN and recorded the concentration-response of beating rate, contractility and the change in the presence or absence of selective ß1, ß2 and ß3 adrenergic blockers. Results: Our results suggested that ISO carries a high risk of inducing arrhythmias, aligning with existing literature. SYN caused a 30% prolongation of the field potential duration (FPD) at a concentration of 206.326 µM, a change significantly different from baseline measurements and control treatments. The half maximal effective concentration (EC50) of SYN (3.31 µM) to affect hiPSC-CM beating rate is much higher than that of ISO (18.00 nM). The effect of SYN at an EC50 of 3.31 µM is about ten times more potent in hiPSC-CMs compared to neonatal rat cardiomyocytes (34.12 µM). SYN increased the contractility of cardiomyocytes by 29.97 ± 11.65%, compared to ISO's increase of 50.56 ± 24.15%. ß1 receptor blockers almost eliminated the beating rate increase induced by both ISO and SYN, while neither ß2 nor ß3 blockers had a complete inhibitory effect. Conclusion: The MEA and hiPSC-CM system could effectively predict the risk of adrenomimetic drugs. The study concludes that the proarrhythmia risk of SYN at conventional doses is low. SYN is more sensitive in increasing beating rate and contractility in human cardiomyocytes compared to rats, primarily activating ß1 receptor.

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Vincristine (VCR), a vinca alkaloid with anti-tumor and anti-oxidant properties, is acclaimed to possess cardioprotective action. However, the molecular mechanism underlying this protective effect remains unknown. This study investigated the effects of VCR on isoprenaline (ISO), a beta-adrenergic receptor agonist, induced cardiac hypertrophy in male Wistar rats. Animals were pre-treated with ISO (1 mg/kg) intraperitoneally for 14 days before VCR (25 µg/kg) intraperitoneal injection from days 1 to 28. Thereafter, mechanical, and electrical activities of the hearts of the rats were measured using a non-invasive blood pressure monitor and an electrocardiograph, respectively. After which, the heart was homogenized, and supernatants were assayed for contractile proteins: endothelin-1, cardiac troponin-1, angiotensin-II, and creatine kinase-MB, with markers of oxidative/nitrergic stress (SOD, CAT, MDA, GSH, and NO), inflammation (TNF-a and IL-6, NF-kB), and caspase-3 indicative of VCR reduced elevated blood pressure and reversed the abnormal electrocardiogram. ISO-induced increased endothelin-1, cardiac troponin-1, angiotensin-II, and creatine phosphokinase-MB, which were reversed by VCR. ISO also increased TNF-α, IL-6, NF-kB expression with increased caspase-3-mediated apoptosis in the heart. However, VCR reduced ISO-induced inflammation and apoptosis, with improved endogenous antioxidant agents (GSH, SOD, CAT) relative to ISO controls. Moreso, VCR, protected against ISO-induced histoarchitectural degeneration of cardiac myofibre. The result of this study revealed that VCR treatment significantly reverses ISO-induced cardiac hypertrophic phenotypes, via mechanisms connected to improved levels of proteins involved in excitation-contraction, and suppression of oxido-inflammatory and apoptotic pathways.

Asunto(s)

Antioxidantes , Apoptosis , Modelos Animales de Enfermedad , Isoproterenol , FN-kappa B , Óxido Nítrico , Estrés Oxidativo , Ratas Wistar , Especies Reactivas de Oxígeno , Transducción de Señal , Vincristina , Animales , Masculino , Transducción de Señal/efectos de los fármacos , FN-kappa B/metabolismo , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Vincristina/farmacología , Especies Reactivas de Oxígeno/metabolismo , Antioxidantes/farmacología , Óxido Nítrico/metabolismo , Mediadores de Inflamación/metabolismo , Cardiomegalia/inducido químicamente , Cardiomegalia/patología , Cardiomegalia/metabolismo , Cardiomegalia/tratamiento farmacológico , Cardiomegalia/prevención & control , Ratas , Antiinflamatorios/farmacología , Miocardio/patología , Miocardio/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Miocitos Cardíacos/metabolismo , Remodelación Ventricular/efectos de los fármacos

RESUMEN

Takotsubo syndrome (TTS) is a stress-induced cardiomyopathy, characterized by an increased concentration of catecholamines, free radicals, and inflammatory cytokines, endothelial dysfunction, and increased apoptotic activity. High doses of isoprenaline are used in animal models to induce Takotsubo (TT)-like myocardial injury. The aim of the study was to investigate the antiapoptotic effects of liraglutide in experimental TTS and its role in the NF-κB pathway. Wistar rats were pretreated with liraglutide for 10 days, and on days 9 and 10, TT-like myocardial injury was induced with isoprenaline. After the sacrifice on day 11, hearts were isolated for histopathological and immunohistochemical analysis. Liraglutide reduced isoprenaline-induced cardiomyocyte apoptosis by decreasing cleaved caspase-3 (CC3), BCL-2-associated X protein (BAX), and NF-κB and increasing B-cell lymphoma/leukemia-2 (BCL-2). An increase in NF-κB in isoprenaline-treated rats was in positive correlation with proapoptotic markers (BAX and CC3) and in negative correlation with antiapoptotic marker BCL-2. Liraglutide increased BCL-2 and decreased NF-κB, BAX, and CC3, preserving the same correlations of NF-κB to apoptotic markers. It is concluded that liraglutide protects cardiomyocytes against isoprenaline-induced apoptosis in experimental TT-like myocardial injury through downregulation of the NF-κB pathway.

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Objective: Myocardial infarction (MI) is linked to an imbalance in the supply and demand of blood oxygen in the heart muscles. Beta-blockers and calcium antagonists are just two of the common medications used to treat MI. However, these have reportedly been shown to be either ineffective or to have undesirable side effects. Extract of Ginkgo biloba leaves (GBE), a Chinese herbal product offers special compatibility benefits in therapeutic settings relating to inflammatory diseases and oxidative stress. In order to better understand how GBE affects MI in rats insulted by isoprenaline (ISO), the current study was designed. Methods: The heart weight index, serum lipid profile, cardiac marker enzymes, endogenous antioxidants [catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), nitrites and malondialdehyde (MDA)], inflammatory mediators [tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6)], immunohistochemical expressions of B-cell lymphoma factor-2 (Bcl-2), extracellular signal-regulated kinase (ERK1/2), and mammalian target of rapamycin (mTOR) and histopathological analysis were used to assess the cardioprotective properties of GBE. Results: The findings showed that GBE effectively attenuated myocardial infarction by boosting the body's natural antioxidant defense system and reducing the release of inflammatory cytokines as well as heart injury marker enzymes. The expression of Bcl-2, ERK1/2 and mTOR was increased while the histomorphological alterations were reversed. Conclusion: The cardioprotective effects of GBE may be due to a mechanism involving increased Bcl-2/mTOR/ERK1/2/Na+, K+-ATPase activity.

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Pathological cardiac hypertrophy often precedes heart failure due to various stimuli, yet effective clinical interventions remain limited. Recently, microRNAs (miRNAs) have been identified as critical regulators of cardiovascular development. In this study, we investigated the role of miR-146b-5p and its underlying mechanisms of action in cardiac hypertrophy. Isoprenaline (ISO) treatment induced significant hypertrophy and markedly enhanced the expression of miR-146b-5p in cultured neonatal rat cardiomyocytes and hearts of C57BL/6 mice. Transfection with the miR-146b-5p mimic led to cardiomyocyte hypertrophy accompanied by autophagy inhibition. Conversely, miR-146b-5p inhibition significantly alleviated ISO-induced autophagy depression, thereby mitigating cardiac hypertrophy both in vitro and in vivo. Our results showed that the autophagy-related mediator double FYVE domain-containing protein 1 (DFCP1) is a target of miR-146b-5p. MiR-146b-5p blocked autophagic flux in cardiomyocytes by suppressing DFCP1, thus contributing to hypertrophy. These findings revealed that miR-146b-5p is a potential regulator of autophagy associated with the onset of cardiac hypertrophy, suggesting a possible therapeutic strategy involving the inhibition of miR-146b-5p.

Asunto(s)

Autofagia , Cardiomegalia , Isoproterenol , Ratones Endogámicos C57BL , MicroARNs , Miocitos Cardíacos , Animales , MicroARNs/genética , MicroARNs/metabolismo , Isoproterenol/farmacología , Cardiomegalia/genética , Cardiomegalia/inducido químicamente , Cardiomegalia/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Autofagia/efectos de los fármacos , Autofagia/genética , Ratas Sprague-Dawley , Ratas , Masculino , Ratones , Células Cultivadas , Regulación de la Expresión Génica/efectos de los fármacos , Proteínas Relacionadas con la Autofagia/genética , Proteínas Relacionadas con la Autofagia/metabolismo , Secuencia de Bases

RESUMEN

P2X7 receptor (P2X7R) plays an important role in modulating inflammation and fibrosis, but information is limited whether Zusanli (ST36) can inhibit inflammation and fibrosis by regulating P2X7R. Isoprenaline at 5 mg/kg was subcutaneously injected to wild-type and P2X7R knockout mice for 7 days, while treatment groups received electroacupuncture (EA) stimulation at ST36 for 7 sessions. Following 7-session treatment, Masson's trichrome staining was performed to assess the fibrosis. Morphology, electrocardiogram, and echocardiography were carried out to evaluate the cardiac function and structure. Western blotting, hematoxylin and eosin staining, immunohistochemistry, and biochemical analysis of inflammatory cytokine and transmission electron microscopy were carried out to characterize the effect of ST36 on inflammation. P2X7R was overexpressed in ISO-treated mice. EA at ST36, but not at non-points, reduced ISO-induced cardiac fibrosis, increases in HW/BW, R+S wave relative to mice in ISO groups. In addition, EA at ST36 downregulated ISO-upregulated P2X7R and NLRP3 in ventricle. Moreover, EA reduced cytokines of IL-1ß, IL-6, and IL-18 in serum, and inhibited foam cell gathering, inflammatory cell infiltration, and autophagy. However, EA at ST36 failed to attenuate the cardiac fibrosis and hypertrophy in P2X7R knockout mice. In conclusion, EA at ST36 attenuated ISO-induced fibrosis possibly via P2X7R.

RESUMEN

[This corrects the article DOI: 10.3389/fphar.2023.1305816.].

RESUMEN

Introduction: Retrograde intrarenal surgery (RIRS) is associated with complications, many of which are related to the intrarenal pressure (IRP). We aim to describe the design of a novel isoprenaline-eluting guidewire ("IsoWire") and present the results from the first in vitro release studies and the first animal studies showing its effect on IRP. Materials and Methods: The IsoWire comprises a Nitinol core surrounded by a stainless-steel wire wound into a tight coil. The grooves created by this coil provided a reservoir for adding a hydrogel coating into which isoprenaline, a beta-agonist, was loaded. Animal studies were performed using a porcine model. For the control, IRP, heart rate (HR), and mean arterial pressure (MAP) were measured continuously for 6 minutes with a standard guidewire in place. For the experiment, the standard hydrophilic guidewire was removed, the IsoWire was inserted into the renal pelvis, and the same parameters were measured. Results: In vitro analysis of the isoprenaline release profile showed that most (63.9 ± 5.9%) of the loaded drug mass was released in the 1st minute, and almost all of the drug was released in the first 4 minutes exponentially. Porcine studies showed a 25.1% reduction in IRP in the IsoWire that released 10 µg in the 1st minute; however, there was a marked increase in HR. The average percentage reduction in IRP was 8.95% and 21.3% in the IsoWire that released 5 and 7.5 µg of isoprenaline, respectively, with no changes in HR or MAP. Conclusions: The IsoWire, which releases 5 and 7.5 µg of isoprenaline in the 1st minute, appears to be safe and effective in reducing the IRP. Further studies are needed to establish whether the isoprenaline-induced ureteral relaxation will render easier insertion of a ureteral access sheath, reduce IRP during sheathless RIRS, or even promote the practice of sheathless RIRS.

Asunto(s)

Isoproterenol , Animales , Proyectos Piloto , Porcinos , Isoproterenol/farmacología , Diseño de Equipo , Riñón/cirugía

RESUMEN

The aim of this study was to evaluate the effect of l-carnitine (L-CAR) treatment on isoprenaline (ISO) administered kidney and heart impairment in male Long Evans rats. Four groups of rats were engaged in this study such as control, ISO, control + L-CAR, and ISO + L-CAR, where n = 6 in each group. The rats were also provided with chow food and water ad libitum. At the end of the study, all rats were sacrificed, and blood and tissue samples were collected for bio-chemical analysis. Oxidative stress parameters and antioxidant enzyme activities were determined in plasma and tissues. Antioxidant and inflammatory genes expression were analyzed in the kidney cortex, and histopathological studies of kidney tissues were performed. This study showed that creatinine and uric acid in plasma were significantly increased in ISO-administered rats. l-carnitine treatment lowered the uric acid and creatinine level. ISO-administered rats showed increased lipid peroxidation and declined levels of antioxidant enzymes activities in kidneys and heart. l-carnitine treatment restored antioxidant enzymes activities and protect against oxidative stress in kidney and heart. This effect is correlated with the restoration of Nrf-2-HO-1 genes expression followed by increased SOD and catalase genes expression in the kidney. l-carnitine treatment also prevented the TNF-α, IL-6, and NF-кB expression in kidneys of ISO administered rats. Histopathology staining showed that l-carnitine treatment prevented kidney damage and collagen deposition in ISO administered rats. The result of this study exhibited that l-carnitine treatment reduced oxidative stress and increased antioxidant enzyme activities by enhancing antioxidant genes expression in ISO administered rats.

RESUMEN

Heart failure represents a major cause of death worldwide. Recent research has emphasized the potential role of protein ubiquitination/deubiquitination protein modification in cardiac pathology. Here, we investigate the role of the ovarian tumor deubiquitinase 1 (OTUD1) in isoprenaline (ISO)- and myocardial infarction (MI)-induced heart failure and its molecular mechanism. OTUD1 protein levels were raised markedly in murine cardiomyocytes after MI and ISO treatment. OTUD1 deficiency attenuated myocardial hypertrophy and cardiac dysfunction induced by ISO infusion or MI operation. In vitro, OTUD1 knockdown in neonatal rat ventricular myocytes (NRVMs) attenuated ISO-induced injuries, while OTUD1 overexpression aggravated the pathological changes. Mechanistically, LC-MS/MS and Co-IP studies showed that OTUD1 bound directly to the GAF1 and PDEase domains of PDE5A. OTUD1 was found to reverse K48 ubiquitin chain in PDE5A through cysteine at position 320 of OTUD1, preventing its proteasomal degradation. PDE5A could inactivates the cGMP-PKG-SERCA2a signaling axis which dysregulate the calcium handling in cardiomyocytes, and leading to the cardiomyocyte injuries. In conclusion, OTUD1 promotes heart failure by deubiquitinating and stabilizing PDE5A in cardiomyocytes. These findings have identified PDE5A as a new target of OTUD1 and emphasize the potential of OTUD1 as a target for treating heart failure.

Asunto(s)

Insuficiencia Cardíaca , Infarto del Miocardio , Ratones , Ratas , Animales , Isoproterenol/farmacología , Miocitos Cardíacos/metabolismo , Cromatografía Liquida , Espectrometría de Masas en Tándem , Insuficiencia Cardíaca/metabolismo , Infarto del Miocardio/metabolismo

RESUMEN

Background: Isoprenaline (ISO), a synthetic catecholamine and a ß-adrenoceptor agonist, is widely used to develop an experimental model of myocardial injury (MI) in rats. The leading hypothesis for ISO-induced MI in rats is that it results from catecholamine overstimulation, oxidative stress, inflammatory responses, and development of cardiomyopathy during ISO administration. Folic acid (FA) reduces oxidative stress, improves endothelial function and prevents apoptosis, thereby contributing to cardiovascular protection. This study aimed to investigate the potentially protective effect of FA pretreatment on ISO-induced MI in rats. Methods: For 7 days, adult male Wistar albino rats were pretreated with 5 mg/kg/day of FA. On the sixth and seventh days, MI in rats was induced by administering 85 mg/kg/day of ISO. Prooxidant markers in plasma samples, antioxidant capacity in erythrocyte lysates, cardiac damage markers, lipid profile, electrocardiography (ECG) and histopathological analysis were evaluated. Results: FA pretreatment significantly alleviated changes induced by ISO; it decreased the homocysteine and high-sensitivity troponin I level. FA moderately decreased the reactive oxygen species (ROS) levels (superoxide anion radical, hydrogen peroxide and thiobarbituric acid reactive substances) and improved the antioxidant activities of catalase, superoxide dismutase and reduced glutathione. ISO reduced the nitrite level and FA significantly alleviated this change. Conclusion: It can be concluded that FA, as a mild antioxidant, could be an appropriate cardioprotective substance in the rat model of ISO-induced MI.

Asunto(s)

Antioxidantes , Infarto del Miocardio , Ratas , Masculino , Animales , Isoproterenol/toxicidad , Antioxidantes/farmacología , Antioxidantes/metabolismo , Miocardio/metabolismo , Ratas Wistar , Ácido Fólico/efectos adversos , Ácido Fólico/metabolismo , Peroxidación de Lípido , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo

RESUMEN

Prolonged stimulation of ß-adrenergic receptor (ß-AR) can lead to sympathetic overactivity that causes pathologic cardiac hypertrophy and fibrosis, ultimately resulting in heart failure. Recent studies suggest that abnormal protein ubiquitylation may contribute to the pathogenesis of cardiac hypertrophy and remodeling. In this study, we demonstrated that deficiency of a deubiquitinase, Josephin domain-containing protein 2 (JOSD2), ameliorated isoprenaline (ISO)- and myocardial infarction (MI)-induced cardiac hypertrophy, fibrosis, and dysfunction both in vitro and in vivo. Conversely, JOSD2 overexpression aggravated ISO-induced cardiac pathology. Through comprehensive mass spectrometry analysis, we identified that JOSD2 interacts with Calcium-calmodulin-dependent protein kinase II (CaMKIIδ). JOSD2 directly hydrolyzes the K63-linked polyubiquitin chains on CaMKIIδ, thereby increasing the phosphorylation of CaMKIIδ and resulting in calcium mishandling, hypertrophy, and fibrosis in cardiomyocytes. In vivo experiments showed that the cardiac remodeling induced by JOSD2 overexpression could be reversed by the CaMKIIδ inhibitor KN-93. In conclusion, our study highlights the role of JOSD2 in mediating ISO-induced cardiac remodeling through the regulation of CaMKIIδ ubiquitination, and suggests its potential as a therapeutic target for combating the disease. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary. All have been checked.

Asunto(s)

Insuficiencia Cardíaca , Miocitos Cardíacos , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Cardiomegalia/inducido químicamente , Fibrosis , Insuficiencia Cardíaca/inducido químicamente , Isoproterenol/farmacología , Remodelación Ventricular

RESUMEN

Aim To investigate the regulatory effect of Cortaetin on pathological myocardial hypertrophy induced by isoprenaline (ISO) and the underlying mechanism. Methods ISO was used to stimulate neonatal rat cardiomyocytes for 24 h, and myocardial hypertrophy model was established at the cellular level. C57BL/6 mice were injected subcutaneously with ISO for one week to establish myocardial hypertrophy model at animal level. RT-qPCR was used to detect the changes of mRNA and Western blot was used to detect the changes of relative protein content. Immunofluorescence was used to measure the subcellular location of Cortaetin and the change of its expression. The overex-pression of Cortaetin by adenovirus infection and the knockdown of Cortaetin by transfection of small interfering RNA were studied. Results On the cellular and animal levels, ISO-induced myocardial hypertrophy models were successfully established, and it was observed that ISO caused the decrease of Cortaetin and N-cadherin protein levels. Overexpression of Cortaetin could reverse the decrease of N-cadherin protein level and myocardial hypertrophy caused by ISO. Knockdown of Cortaetin showed the opposite effect. Conclusion Cortaetin, in combination with N-cadherin, may play a role in combating myocardial hypertrophy by enhancing the connections between cardiomyocytes.

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Objective To compare animal models of chronic heart failure(CHF)prepared by three different protocols,to establish a stable,reliable,and reproducible mouse model of CHF.Methods Twenty-five male C57BL/6J mice were divided randomly into four groups:a blank group,model A group(MA group),model B group(MB group),and model C group(MC group).The model groups adopted different preparation protocols for continuous injection of isoprenaline.The MA group and MB group were dose-decreasing models:MA group:subcutaneous injection of 10 mg/kg on day 1,5 mg/kg on day 2,2.5 mg/(kg·d)on days 3～30,total 30 days;and MB group:subcutaneous injection of 20 mg/kg on day 1,10 mg/kg on day 2,5 mg/(kg·d)on days 3～14,total 14 days.The MC group used a constant dose of intraperitoneal injection of 7.5 mg/(kg·d)for 28 days.The day after the final injection,the survival and model-formation rates for each group of mice were calculated.Cardiac function was measured by cardiac ultrasound and serum levels of N-terminal pro B-type natriuretic peptide,interleukin-6,and tumor necrosis factor-α were measured.Results CHF was successfully induced in all the model groups after all injections at the end of the fourth week.However,comprehensive test result showed that the MC model was the most stable.Conclusions An isoprenaline-induced mouse model of CHF using constant intraperitoneal injection of 7.5 mg/(kg·d)for 28 days may be the most suitable model for subsequent research on traditional Chinese medicine.

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AIM: Cardiac fibrosis is characterized by excessive accumulation of fibrous tissue, particularly collagens, in the myocardium. Accumulated fibrous tissue renders myocardium stiffer and reduces its contractility. Empagliflozin is an oral hypoglycemic agent with extra-diabetic functional profile toward maintaining cardiac functions. The present study aimed to examine protective effect of empagliflozin against an in-vivo model of cardiac fibrosis induced by isoprenaline and targeting TGF-ß/SMAD signaling as a possible pathway responsible for such effect. MAIN METHODS: Sixty animals were divided into six groups; the first was normal, and the second was treated with isoprenaline only (5 mg/kg/day I.P.) as a control. The third received pirfenidone (500 mg/kg/day P.O.), and the remaining groups received graded doses (5, 10, 20 mg/kg respectively) of empagliflozin for 14 days before fibrosis induction by isoprenaline (5 mg/kg/day) for 30 days. KEY FINDINGS: Isoprenaline increased cardiac enzymes, and cardiac tissues revealed elevated concentrations of transforming growth factor ß (TGF-ß1), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor α (TNF-α), and c-jun N-terminal kinase (JNK) proteins. Expression of nuclear factor kappa B (NF-κB), alpha smooth muscle actin (α-SMA), collagens, suppressor of mothers against decapentaplegic (SMADs), connective tissue growth factor (CTGF), and fibronectin was upregulated. Empagliflozin improved the histological picture of heart tissue in comparison to fibrosis developed in controls, and protected against fibrosis through significant modulation of all mentioned parameters' concentrations and expressions. SIGNIFICANCE: Empagliflozin demonstrated a promising protective approach against biological model of cardiac fibrosis through an anti-fibrotic effect through targeting TGF-ß signaling pathways.

Asunto(s)

Transducción de Señal , Factor de Crecimiento Transformador beta , Ratas , Animales , Factor de Crecimiento Transformador beta/metabolismo , Isoproterenol/toxicidad , Factor de Crecimiento Transformador beta1/metabolismo , Fibrosis , Colágeno/farmacología

RESUMEN

Unstable and symptomatic complete atrioventricular block represents a potentially fatal condition that requires prompt therapy while waiting for definitive pacemaker implantation. Although transcutaneous pacing is included in acute management, it could be a difficult approach due to its painfulness and the occasional failure of mechanical capture. Drug therapy is a feasible choice, and current guidelines encompass the use of atropine, dopamine, or epinephrine. Isoprenaline has never been investigated in this setting, and no specific indication of its use has been provided despite its potentially more favorable pharmacological profile. The study population included a consecutive series of patients who presented to the emergency department because of unstable third-degree atrioventricular block and were treated with either isoprenaline or dopamine infusion while waiting for definitive pacemaker implantation. Asymptomatic patients or those with reversible causes of complete atrioventricular block were excluded. The clinical response to the drug was deemed poor if, despite achieving a full drug dose, patients remained symptomatic and/or with hemodynamic instability, ventricular rate and rhythm did not improve or worsened, including if ventricular arrhythmias or asystolic pauses and/or irrepressible nausea/vomiting occurred. Isoprenaline infusion has proved to be safe and tolerated with no arrhythmia induction or hypotensive issues. Isoprenaline has also proven to be more satisfactory in achieving an effective clinical response in 84% of patients rather than dopamine (31%, p < 0.001), reducing the need for temporary artificial pacing. Our data point out the efficacy and safety of isoprenaline infusion and its greater tolerability over dopamine in the acute management of unstable third-degree AV block while waiting for definitive pacemaker implantation.

RESUMEN

The pyrimidine nucleoside uridine and its phosphorylated derivates have been shown to be involved in the systemic regulation of energy and redox balance and promote the regeneration of many tissues, including the myocardium, although the underlying mechanisms are not fully understood. Moreover, rearrangements in mitochondrial structure and function within cardiomyocytes are the predominant signs of myocardial injury. Accordingly, this study aimed to investigate whether uridine could alleviate acute myocardial injury induced by isoprenaline (ISO) exposure, a rat model of stress-induced cardiomyopathy, and to elucidate the mechanisms of its action related to mitochondrial dysfunction. For this purpose, a biochemical analysis of the relevant serum biomarkers and ECG monitoring were performed in combination with transmission electron microscopy and a comprehensive study of cardiac mitochondrial functions. The administration of ISO (150 mg/kg, twice with an interval of 24 h, s.c.) to rats caused myocardial degenerative changes, a sharp increase in the serum cardiospecific markers troponin I and the AST/ALT ratio, and a decline in the ATP level in the left ventricular myocardium. In parallel, alterations in the organization of sarcomeres with focal disorganization of myofibrils, and ultrastructural and morphological defects in mitochondria, including disturbances in the orientation and packing density of crista membranes, were detected. These malfunctions were improved by pretreatment with uridine (30 mg/kg, twice with an interval of 24 h, i.p.). Uridine also led to the normalization of the QT interval. Moreover, uridine effectively inhibited ISO-induced ROS overproduction and lipid peroxidation in rat heart mitochondria. The administration of uridine partially recovered the protein level of the respiratory chain complex V, along with the rates of ATP synthesis and mitochondrial potassium transport, suggesting the activation of the potassium cycle through the mitoKATP channel. Taken together, these results indicate that uridine ameliorates acute ISO-induced myocardial injury and mitochondrial malfunction, which may be due to the activation of mitochondrial potassium recycling and a mild uncoupling leading to decreased ROS generation and oxidative damage.

Asunto(s)

Cardiomiopatías , Mitocondrias Cardíacas , Ratas , Animales , Isoproterenol/efectos adversos , Mitocondrias Cardíacas/metabolismo , Uridina/farmacología , Uridina/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Cardiomiopatías/metabolismo , Potasio/metabolismo , Adenosina Trifosfato/metabolismo

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Torsades de pointes (TdP) is a less common type of ventricular tachycardia (VT) characterized by polymorphic VT of changing amplitude and characteristic twists around the isoelectric baseline. It is almost always associated with QT interval prolongation. Unless immediately intervened, it can lead to ventricular fibrillation followed by cardiac arrest. We report a case of a patient with bradycardia-induced TdP who presented to the emergency room with cardiac arrest.

RESUMEN

Canagliflozin (CZ) is commonly prescribed for management of type-2 diabetes mellitus (T2DM); it also can reduce the risk of myocardial infarction. We used 80 albino Wistar rats to investigate the cardioprotective potential of CZ against oxidative stress caused by administration of isoprenaline (ISO). We found that ISO stimulates production of reactive oxygen species and that CZ administration caused up-regulation of antioxidants and down-regulation of oxidants due to nuclear factor erythroid-2 related factor-2, as well as by enhancement of the heme oxygenase-1 mediated cascade. CZ monotherapy may play a cardioprotective role in diabetic patients. CZ possesses strong antioxidant potential that ameliorates cardiac damage induced by ISO administration.

Asunto(s)

Hemo-Oxigenasa 1 , Miocitos Cardíacos , Humanos , Ratas , Animales , Isoproterenol/farmacología , Isoproterenol/metabolismo , Miocitos Cardíacos/metabolismo , Hemo-Oxigenasa 1/metabolismo , Canagliflozina/metabolismo , Estrés Oxidativo , Antioxidantes/farmacología , Antioxidantes/metabolismo , Ratas Wistar