Isoproterenol Group Research Articles

Effects of Intrauterine Isoproterenol Administration on Ovarian Follicular Development in Cows.

Isoproterenol (ISO) is a nonselective beta-adrenergic receptor agonist known for its vasodilatory effects. This experiment aims to investigate whether intrauterine ISO administration could alter vascular indices and follicular development in postpartum Holstein cows. The objectives are to evaluate the effects of intrauterine ISO administration on vascular changes and its impact on follicular development compared to placebo groups. This randomized controlled study was conducted on 36 Holstein cows selected based on their health status, including only those free from reproductive, metabolic and infectious disorders. The cows (n=36) were divided into two groups as control received distilled water alone (CON, n=18) and experiment received 4mg ISO in 40mL distilled water (ISO, n=18) and four subgroups as CON-I (n=9), CON-II (n=9), ISO-I (n=9) and ISO-II (n=9) according to days of intrauterine administration (I or II represents to 1 or 2days after ovulation, respectively). Uterine and ovarian artery blood flows were assessed before and after administration by Doppler ultrasonography. Blood samples were collected both before and after administration (on Day 1 or 2) and on Days 3, 6 and 9 post-ovulation for hormonal analysis. Antral follicle count (AFC) was recorded on the blood sampling days. Data were analysed via mixed model ANOVA. Intrauterine ISO administration significantly increased the pulse rate (PR) in the ovaries (89.4 vs. 65.5bpm, p<0.0001) and uterus (90.6 vs. 64.2bpm, p<0.0001). Early AFC (1-2.9mm) decreased, whereas small AFC (3-4.9mm) increased in the ISO groups. The weighted average antral follicle size (WAAFS) significantly increased in the ISO group but remained unchanged in the controls. Hormonal analysis revealed elevated levels of FSH (626 vs. 468mIU/mL), AMH (61.3 vs. 46.4ng/L), E2 (138 vs. 122ng/L), P4 (15.3 vs. 10.6ng/mL), IGF-1 (62.6 vs. 25.1ng/mL) and IGFBP-3 (28.4 vs. 16.5ng/mL) in the ISO groups (p<0.0001). The findings indicate that intrauterine administration of ISO on Day 1 post-ovulation could be a promising 'adjunct technique' for future research focussed on minimizing dependence on exogenous hormones or improving the sensitivity of follicles to endogenous hormonal signals, thereby potentially enhancing oocyte yield.

Geraniin attenuates isoproterenol-induced cardiac hypertrophy by inhibiting inflammation, oxidative stress and cellular apoptosis.

Geraniin, a polyphenol derived from the fruit peel of Nephelium lappaceum L., has been shown to possess anti-inflammatory and antioxidant properties in the cardiovascular system. The present study explored whether geraniin could protect against an isoproterenol (ISO)-induced cardiac hypertrophy model. Mice in the ISO group received an intraperitoneal injection of ISO (5 mg/kg) once daily for 9 days, and the administration group were injected with ISO after 5 days of treatment with geraniin or spironolactone. Potential therapeutic effects and related mechanisms analysed by anatomical coefficients, histopathology, blood biochemical indices, reverse transcription-PCR and immunoblotting. Geraniin decreased the cardiac pathologic remodeling and myocardial fibrosis induced by ISO, as evidenced by the modifications to anatomical coefficients, as well as the reduction in collagen I/III á1mRNA and protein expression and cross-sectional area in hypertrophic cardiac tissue. In addition, geraniin treatment reduced ISO-induced increase in the mRNA and protein expression levels of interleukin (IL)-6, IL-1β and tumor necrosis factor-α, whereas ISO-induced IL-10 showed the opposite behaviour in hypertrophic cardiac tissue. Further analysis showed that geraniin partially reversed the ISO-induced increase in malondialdehyde and nitric oxide, and the ISO-induced decrease in glutathione, superoxide dismutase and glutathione. Furthermore, it suppressed the ISO-induced cellular apoptosis of hypertrophic cardiac tissue, as evidenced by the decrease in Bcell lymphoma-2 (Bcl-2)-associated X/caspase-3/caspase-9 expression, increase in Bcl-2 expression, and decrease in TdT-mediated dUTP nick-end labeling-positive cells. These findings suggest that geraniin can attenuate ISO-induced cardiac hypertrophy by inhibiting inflammation, oxidative stress and cellular apoptosis.

Synergistic effects of ginsenoside Rb1 and peroxiredoxin 6 in enhancing myocardial injury treatment through anti-inflammatory, anti-oxidative, and anti-apoptotic mechanisms

AimGinsenosides have notable bioactivity in treating cardiovascular diseases, but the mechanisms of their combined use with Peroxiredoxin 6 (PRDX6) in myocardial injury remain unclear. This study explores the synergistic effects of Ginsenoside Rb1 (Gs-Rb1) and PRDX6, aiming to provide a theoretical foundation for their therapeutic potential. MethodsWe established a rat model of isoproterenol (ISO)-induced myocardial injury and observed that combination therapy was more effective than single-drug treatments, as shown by ECG monitoring and Masson staining. We performed RNA sequencing (RNA-Seq) on the combination therapy group and the ISO group. The results indicated that, compared to the ISO group, the combination therapy alleviated myocardial injury by reducing inflammation, oxidative stress, and apoptosis. Further analyses, including cell morphology, apoptosis rates, HE staining, ROS fluorescence intensity, and inflammation-related proteins, confirmed that the combination therapy successfully inhibited apoptosis, managed oxidative stress, and lessened inflammation. ResultsCombined treatment with Gs-Rb1 and PRDX6 significantly inhibited cardiac tissue fibrosis in rats, leading to a marked decrease in serum CK and LDH levels. RNA-seq analysis revealed upregulated genes related to lipid metabolism and small molecule biosynthesis, while downregulated genes were associated with oxidative stress, inflammation, and apoptosis. Validation experiments confirmed the combined treatment's significant inhibition of apoptosis, ROS activity, and inflammation. These results support the effectiveness of the two-drug combination in suppressing key biological processes in cardiac tissue, suggesting potential mechanisms for combating cardiac fibrosis. ConclusionThis study clarifies how Gs-Rb1 and PRDX6 work together to protect against myocardial damage, demonstrating that their combined therapy reduces inflammation, apoptosis, and oxidative stress. This highlights a new avenue for developing ginseng-based treatments.

Cardioprotective effects of H3 receptor activation could be double-sided: insights from isoproterenol-induced cardiac injury.

Histamine H3 receptors (H3Rs) are known to modulate neurotransmitter release in the nervous system, but their role in cardiac injury remains unclear. The present study aimed to investigate the cardioprotective role of H3Rs in a mouse model of myocardial injury. Forty BALB/c male mice were divided into four groups: Control (SF), Isoproterenol (ISO), Imetit (IMT), and IMT + ISO. The IMT and IMT + ISO groups were pretreated orally with 10mg/kg imetit-dihydrobromide(imetit) for 7days. In the last 2days, the ISO and IMT + ISO groups received a subcutaneous injection of 85mg/kg isoproterenol to induce myocardial ischemia. Electrocardiogram (ECG) recordings were obtained, and heart tissues were analyzed histopathologically. The results demonstrated that the administration of imetit resulted in the prolongation of the PR interval in the IMT group. QRS and QT intervals were prolonged in the ISO group. The J-wave area in the ISO group was significantly larger than in the other groups. Histopathological analyses revealed the presence of small vacuoles, inflammatory cell infiltration, and collagen aggregates in cardiomyocytes in the ISO group. No significant cellular changes were observed in the IMT group, in contrast. The IMT + ISO group exhibited fewer ischemic findings than the ISO group. Immunohistochemical analyses revealed positive H3R immunoreactivity in all groups. Imetit pretreatment increased the immunoreactivity of H3Rs in both the IMT and IMT + ISO groups. The findings of this study suggest that H3Rs may be present on the postsynaptic side in cardiac myocytes, in addition to adrenergic presynaptic nerve endings. Furthermore, imetit has been found to significantly reduce the effects of myocardial ischemia by activating H3Rs. The better characterization of the postsynaptic role of H3Rs offers potential for the development of new therapeutic strategies.

Takotsubo syndrome induced oxidative stress and endothelial dysfunction in left ventricle of rat model: association with NADPH oxidases/SGLT2 pro- oxidant pathway

Abstract Background Takotsubo syndrome (TTS) is characterized by apical ballooning predominantly affecting post-menopausal women following extreme physical and/or emotional stress. The phenotype of TTS is associated with akinetic apex and hyperkinetic base of the left ventricle (LV). Presently, there are no targeted therapies for TTS that can effectively reduce LV impairment. Empagliflozin (EMPA), an SGLT2 inhibitor, has shown considerable clinical benefits in managing heart failure. However, its specific effects and underlying mechanisms in treating TTS remain unclear. Purpose To explore the pathophysiology of TTS in the LV of rats, with a particular focus on the potential role of SGLT2, and to elucidate the underlying mechanisms involved. Methods Female Sprague Dawley rats (250-300 g) were allocated into four groups: a control group (n=8), a group treated with EMPA (30 mg/kg/day) (n=8), a group receiving ISO (Isoproterenol) at 100 mg/kg/day (n=18), and a group receiving both ISO and EMPA (IE) at 30 mg/kg/day (n=18). EMPA was administered orally through food two weeks prior to ISO injection. Echocardiography was conducted at 6 and 24 h, and on day 3. On day 3, rats were euthanized, and their organs were collected. Gene expression of markers was assessed using RT-qPCR, protein expression via immunofluorescence (IF) staining, and oxidative stress using dihydroethidium. Results In the ISO group, the success rate of induced Takotsubo syndrome (TTS) was 53% (10 out of 18 rats), with a mortality rate of 5%. Conversely, in the EMPA-treated group, TTS occurred in 22% of rats (4 out of 18) with no mortality observed. Significant reductions in the area of left ventricular (LV) ballooning and ejection fraction were noted in the IE group compared to the ISO group. Additionally, increased levels of reactive oxygen species (ROS) were observed in the LV of ISO rats, which were normalized by EMPA treatment in the IE rats. Furthermore, the ISO group exhibited higher protein expressions of CD68, SGLT2, and VCAM-1, which were attenuated by EMPA treatment. The mRNA expression of CYBA (p22phox) and NOX4, both representing subunits of NADPH oxidases, along with VCAM1, ICAM1, NOS2 (iNOS) and SELE (e-selectin) gene, endothelial activation marker, and TGF-β1, a fibrotic marker, showed elevated levels in the apex part of the left ventricle (LV) in the ISO group; these levels were significantly lower in the IE group. Conclusions These findings suggest that TTS is associated with oxidative stress-mediated endothelial dysfunction, inflammation, and pro-fibrotic responses. Moreover, SGLT2 inhibition appears to mitigate the pathology and progression of the syndrome. Therefore, SGLT2 inhibition emerges as an appealing and novel therapeutic approach for the treatment of TTS.

Mitigating effects of agmatine on myocardial infarction in rats subjected to isoproterenol.

Isoproterenol (ISO) usage is limited by its potential for cardiotoxicity. We sought to investigate the potential of agmatine in mitigating ISO-induced cardiotoxicity. Agmatine (100mg/kg/day) was intraperitoneally administered to Wistar rats for 7days in the presence or absence of cardiotoxicity induced by subcutaneous injection of ISO (85mg/kg) on the sixth and seventh days. ECG parameters, lactate dehydrogenase (LDH), malondialdehyde (MDA), and creatinine phosphokinase (CPK) were investigated. Changes in cardiac tissue were also investigated using H&E staining. The heart weight/body weight ratio increased in ISO-treated rats. In the agmatine + ISO group, the increased heart rate observed in ISO-treated rats was reversed (317.2 ± 10.5 vs 452.2 ± 10.61, P < 0.001). Agmatine ameliorated the change in PR, RR, and ST intervals and the QRS complex, which was reduced by ISO. Treatment with saline, ISO, and agmatine had no significant effect on papillary muscle stimulation (P > 0.05). The administration of agmatine to ISO-receiving group could mitigate several parameters when compared to ISO-receiving group including increasing papillary muscle contraction (0.83 vs 0.71 N/M2 respectively, P < 0.01), decreasing LDH levels (660ng/ml vs 1080ng/ml, respectively, P < 0.05), decreasing CPK levels (377 U/l vs 642 U/l, respectively, P < 0.05) and decreasing MDA levels (20.32µM/l vs 46.83µM/l, P < 0.001). Coadministration of agmatine and ISO is capable of ameliorating ISO cardiotoxicity by antioxidant effects and controlling the hemostasis of calcium in myocytes.

The effect of eight-week resistance training on oxidative stress in isoproterenol-induced myocardial infarction in rats.

Although reliable new evidence has identified several advantages of resistance training (ResEx) on cardiac performance, the role of this type of training in protecting the myocardium against ischemia-reperfusion (IR) injury is not clear. The aim of this study was to investigate the effect of resistance training on cardioprotection versus IR-induced injury. 60-day-old male Wistar rats (n = 24), weighing 220-240 g, were divided into four groups: Resistance Training (ResEx), Isoproterenol (ISO), Resistance Training + Isoproterenol (ResEx + ISO), and control groups (n = 6 for each). Trained rats performed exercise in a squat-training apparatus (8-12 repetitions/set, eight sets/day, and 5 days/week for 8 weeks). After the last training session, all the rats were sacrificed with ketamine xylazine injection. The heart of rats was removed from the body and washed quickly with cold PBS, immediately put in liquid nitrogen, and stored at -70°C. Superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activity was measured. Induction of ischemia decreased SOD and CAT activity but had no effect on the activity of GPX. Eight weeks of resistance training significantly increased activity of SOD and CAT compared to the ISO group. The results of the present research demonstrated that ischemia induced by isoproterenol injection during 8 weeks of resistance training did not lead to a decrease in SOD activity and prevented the reduction of CAT activity.

MiR-450a-2-3p targets ERK(1/2) to ameliorate ISO-induced cardiac fibrosis in mice

ObjectiveCardiac fibrosis is an important contributor to atrial fibrillation (AF). Our aim was to identify biomarkers for AF using bioinformatics methods and explore the regulatory mechanism of miR-450a-2-3p in cardiac fibrosis in mice.MethodsTwo datasets, GSE115574 and GSE79768, were obtained from the Gene Expression Omnibus (GEO) database and subsequently merged for further analysis. Differential gene expression analysis was performed to identify differentially expressed genes (DEGs) and miR-450a-2-3p-related differentially expressed genes (MRDEGs). To investigate the underlying mechanism of cardiac fibrosis, a mouse model was established by treating mice with isoproterenol (ISO) and the miR-450a-2-3p agomir.ResultsA total of 127 DEGs and 31 MRDEGs were identified and subjected to Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to determine the functions and pathways involved in AF. In the animal model, histological analysis using HE and Masson staining, as well as quantification of the collagen volume fraction (CVF), was performed. The increased expression of α-smooth muscle actin (α-SMA), collagen type I (COL1), collagen type III (COL3), and extracellular signal-regulated kinase 1/2 (ERK(1/2)) at both the transcriptional and translational levels indicated the significant development of myocardial fibrosis in mice induced with isoproterenol (ISO). In addition, the cross-sectional area of cardiomyocytes and the expression of atrial natriuretic peptide (NPPA) and brain natriuretic peptide (NPPB) were increased in the ISO group compared with the control group. However, after overexpression of the miR-450a-2-3p agomir through caudal vein injection, there was a notable improvement in cardiac morphology in the treated group. The expression levels of α-SMA, COL1, COL3, ERK(1/2), NPPA, and NPPB were also significantly decreased.ConclusionOur study reveals the mechanistic connection between ISO-induced myocardial fibrosis and the miR-450a-2-3p/ERK(1/2) signaling pathway, highlighting its role in the development of cardiac fibrosis. Modulating miR-450a-2-3p expression and inhibiting ERK(1/2) activation are promising approaches for therapeutic intervention in patients with AF.

Alchemilla vulgaris modulates isoproterenol-induced cardiotoxicity: interplay of oxidative stress, inflammation, autophagy, and apoptosis.

Introduction: Isoproterenol (ISO) is regarded as an adrenergic non-selective β agonist. It regulates myocardial contractility and may cause damage to cardiac tissues. Alchemilla vulgaris (AV) is an herbal plant that has garnered considerable attention due to its anti-inflammatory and antioxidant bioactive components. The present investigation assessed the cardioprotective potential of AV towards ISO-induced myocardial damage. Methods: Four groups of mice were utilized: control that received saline, an ISO group (85mg/kg, S.C.), ISO + AV100, and ISO + AV200 groups (mice received 100 or 200mg/kg AV orally along with ISO). Results and discussion: ISO induced notable cardiac damage demonstrated by clear histopathological disruption and alterations in biochemical parameters. Intriguingly, AV treatment mitigates ISO provoked oxidative stress elucidated by a substantial enhancement in superoxide dismutase (SOD) and catalase (CAT) activities and reduced glutathione (GSH) content, as well as a considerable reduction in malondialdehyde (MDA) concentrations. In addition, notable downregulation of inflammatory biomarkers (IL-1β, TNF-α, and RAGE) and the NF-κB/p65 pathway was observed in ISO-exposed animals following AV treatment. Furthermore, the pro-apoptotic marker Bax was downregulated together with autophagy markers Beclin1 and LC3 with in ISO-exposed animals when treated with AV. Pre-treatment with AV significantly alleviated ISO-induced cardiac damage in a dose related manner, possibly due to their antioxidant and anti-inflammatory properties. Interestingly, when AV was given at higher doses, a remarkable restoration of ISO-induced cardiac injury was revealed.

Punicalagin attenuates isoproterenol-induced myocardial infarction through nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1-mediated inhibition of inflammation and cardiac stress markers in experimental animal models.

Myocardial infarction (MI) is a significant global health issue and the leading cause of death. Myocardial infarction (MI) is characterized by events such as damage to heart cells and stress generated by inflammation. Punicalagin (PCN), a naturally occurring bioactive compound found in pomegranates, exhibits a diverse array of pharmacological effects against many disorders. This study aimed to assess the preventive impact of PCN, with its potential anti-inflammatory and antioxidant properties, on myocardial injury caused by isoproterenol (ISO) in rats and elucidate the possible underlying mechanisms. Experimental rats were randomly categorized into four groups: control group (fed a regular diet for 15 days), PCN group (orally administered PCN at 50 mg/kg body weight (b.w.) for 15 days), ISO group (subcutaneously administered ISO (85 mg/kg b.w.) on days 14 and 15 to induce MI), and PCN+ISO group (orally preadministered PCN (50 mg/kg b.w.) for 15 days and administered ISO (85 mg/kg b.w.) on days 14 and 15). The rat cardiac tissue was then investigated for cardiac marker, oxidative stress marker, and inflammatory marker expression levels. PCN prevented ISO-induced myocardial injury, suppressing the levels of creatine kinase-myocardial band, C-reactive protein, homocysteine, cardiac troponin T, and cardiac troponin I in the rats. Moreover, PCN treatment reversed (P<0.01) the ISO-induced increase in blood pressure, attenuated lipid peroxidation markers, and depleted both enzymatic and nonenzymatic markers in the rats. Additionally, PCN inhibited (P<0.01) ISO-induced overexpression of oxidative stress markers (p-38, p-c-Jun N-terminal kinase, and p-extracellular signal-regulated kinase 1), inflammatory markers (nuclear factor-kappa B, tumor necrosis factor-alpha, and interleukin-6), and matrix metalloproteinases and decreased the levels (P<0.01) of apoptosis proteins in the rats. Nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1 (Nrf2/Sirt1) is a major cellular defense protein that regulates and scavenges oxidative toxic substances through apoptosis. Therefore, overexpression of Nrf2/Sirt1 to inhibit inflammation and oxidative stress is considered a novel target for preventing MI. PCN also significantly enhanced the expression of Nrf2/Sirt1 in ISO-induced rats. Histopathological analyses of cardiac tissue revealed that PCN treatment exhibited a protective effect on the heart tissue, mitigating damage. These findings show that by activating the Nrf2/Sirt1 pathway, PCN regulates oxidative stress, inflammation, and apoptosis, hence providing protection against ISO-induced myocardial ischemia.

L-Carvone from Mentha spicata L. Leaves Suppresses Oxidative Stress and Hypertrophy in the Isoproterenol-Induced Rat Model of Cardiac Hypertrophy

The effect of L-Carvone (a natural monoterpene from Mentha spicata L., leaves) in cardiac hypertrophy caused by isoproterenol administration was investigated. Male rats (Wistar) were divided into five groups: Control, diseased, diseased rats with losartan, diseased rats with low-dose L-Carvone, and high-dose L-Carvone. Rats were injected with isoproterenol (5 mg/kg) for 30 days to induce cardiac hypertrophy. Then, simultaneously with Losartan (15 mg/kg), L-Carvone was administered orally at a dosage of 25 mg/kg (low dose) and 100 mg/kg (high dose) treatment. The cardioprotective effect of L-Carvone was evaluated by examining the heart morphometric indices, and ECG analyses. Chronic isoproterenol administration resulted in changes in morphometric indices of the heart, ECG tracings, biochemical parameters such as tissue glucose, proteins, lipid profiles, serum cardiac markers, antioxidants, and histopathological integrity of the heart tissue. When compared with the isoproterenol group, L-Carvone administrated for 30 days ameliorated all these changes in rats significantly (p &lt; 0.05). L-Carvone adequately averted chronic cardiac hypertrophy, most probably through its antioxidant potential.

Multiple organs injury and myocardial energy metabolism disorders induced by isoproterenol

The study sought to assess the detrimental effects of isoproterenol (ISO) on major organs and investigate the potential reversibility of these adverse reactions in mice. Male mice were divided into normal control, 0.2 mg/kg.d and 3.0 mg/kg.d ISO groups, and were subcutaneously administered of the respective doses for 14 consecutive days. Subsequently, a recovery period experiment was conducted, replicating the aforementioned procedure, followed by an additional 2-week recovery period for the mice. Following 14 consecutive days of administration, mice treated with ISO exhibited notable cardiac damage manifested by abnormal ECG patterns, dysregulated energy metabolism, elevated cardiac hypertrophy, and increased heart pathological score. Additionally, the administration of ISO resulted in liver and kidney damage, as evidenced by increased pathological score, serum albumin level, and urea level. Lung damage was also observed, indicated by an increase in lung pathological score. Furthermore, the administration of ISO at a dosage of 3.0 mg/kg.d resulted in a decrease in liver mass index, serum iron content, and an increase in lung mass index. After a 2-week recovery period, mice treated with ISO showed abnormalities in ECG patterns and dysregulated myocardial energy metabolism, accompanied by a decrease in serum iron content. Histopathological examinations revealed continued pathological changes in the heart and lung, as well as significant hemosiderin deposition in the spleen. Furthermore, the group treated with ISO at a dosage of 3.0 mg/kg.d showed an increase in serum AST and TP levels. In summary, the study demonstrates that both 0.2 mg/kg.d and 3.0 mg/kg.d doses of ISO can induce damage to the heart, liver, lung, kidney, and spleen, with the higher dose causing more severe injuries. After a 2-week withdrawal period, the liver, kidney, and thymus injuries caused by 0.2 mg/kg ISO shows signs of recovery, while damage to the heart, lung, and spleen persists. The thymus injury mostly recovers, with minimal kidney pathology, but significant damage to the heart, liver, and lung remains even after the withdrawal period for the 3.0 mg/kg ISO dose.

Resveratrol-Based Liposomes Improve Cardiac Remodeling Induced by Isoproterenol Partially by Modulating MEF2, Cytochrome C and S100A1 Expression.

Isoproterenol (ISO), a chemically synthesized catecholamine, belongs to β-adrenoceptor agonist used to treat bradycardia. The β-adrenergic agonist is an essential regulator of myocardial metabolism and contractility; however, excessive exposure to ISO can initiate oxidative stress and inflammation. This study aims to investigate the molecular mechanisms underlying ISO-induced cardiac remodeling, the protective efficacy of resveratrol (RSVR), and its liposomal formulation (L-RSVR) against such cardiac change. Wistar albino rats were evenly divided into 4 groups. Control group, ISO group received ISO (50mg/kg, s.c.) twice a week for 2weeks, and RSVR- and L-RSVR-treated groups in which rats received either RSVR or L-RSVR (20mg/kg/day, p.o.) along with ISO for 2weeks. ISO caused a significant elevation of the expression levels of BAX and MEF2 mRNA, S100A1 and cytochrome C proteins, as well as DNA fragmentation in cardiac tissue compared to the control group. Treatment with either RSVR or L-RSVR for 14days significantly ameliorated the damage induced by ISO, as evidenced by the improvement of all measured parameters. The present study shows that L-RSVR provides better cardio-protection against ISO-induced cardiac injury in rats, most likely through modulation of cardiac S100A1 protein expression and inhibition of inflammation and apoptosis.

Pharmacological inhibition of ICOS attenuates the protective effect of exercise on cardiac fibrosis induced by isoproterenol

AimsTo investigate the cardioprotective mechanism of exercise or exercise combined with inducible costimulatory molecules (ICOS) monoclonal antibody (mAb) therapy against isoproterenol (ISO)-induced cardiac remodeling. Main methodsTotally 24 male C57BL/6J mice were randomly divided into four groups: the control group (normal saline treatment), ISO group (subcutaneous injection of isoproterenol, 10 mg/kg/day, once daily for 5 consecutive days), the exercise with subcutaneous ISO injection group (EPI), and the exercise with injected with ISO and ICOS mAb group (EPII). The mice in EPI and EPII group were trained on a small animal treadmill for 4 weeks (13 m/min, 0% grade, 60min/day). Key findingsExercise significantly attenuated CD45+, Mac-2 inflammatory cell infiltration, cardiac fibrosis and inhibited the RIPK1/RIPK3/MLKL/CaMKII and cardiomyocyte pyroptosis pathways to counter ISO-induced severe cardiac injury. The administration of the ICOS mAb may inhibit the cardioprotection of exercise against ISO-induced heart damage. Compared to those in EPI, our data showed that the increasing levels of myocardial fibrosis, the leukocyte infiltration of cardiac tissue and proteins expression of cardiac myocyte necrosis and pyroptosis signaling pathways in the EPII group. SignificanceOur results demonstrated that exercise decreased leukocyte infiltration in heart, inhibited the cardiomyocyte pyroptosis and necroptosis signaling pathways, and attenuated inflammatory responses to alleviate ISO-induced cardiac fibrosis. However, the antifibrotic effects of combined treatment with exercise and ICOS mAb intervention did not exhibit synergistic enhancement.

Artemisinin Attenuates Isoproterenol-induced Cardiac Hypertrophy via the ERK1/2 and p38 MAPK Signaling Pathways.

Artemisinin (ART) is mainly derived from Artemisia annua, a traditional Chinese medicinal plant, and has been found to affect cellular biochemical processes, such as proliferation, angiogenesis, and apoptosis, in addition to its antimalarial properties. However, its effect on cardiac hypertrophy and the underlying mechanisms remain unclear. This study aimed to investigate the effect of ART on cardiac hypertrophy and explore its possible mechanisms. A rat model was established by intraperitoneal injection of isoproterenol (ISO) for 3 days, and the degree of myocardial hypertrophy was compared among 5 groups: a control (CON) group, an ISO group, and groups treated with different doses of ART (7 mg/kg/d, 35 mg/kg/d, and 75 mg/kg/d). Echocardiography was used to evaluate cardiac function and structure. The cross-sectional area of cardiomyocytes was measured by hematoxylin and eosin (H&E) staining. The heart weight (HW), body weight (BW), and tail length were measured, and the HW/tail length ratio and the HW/BW ratio were calculated. H9c2 rat cardiomyocytes were cultured, and different amounts of ART were added 2 hours before ISO stimulation. Phalloidin staining was used to evaluate the degree of cell hypertrophy. The levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were quantified in rat plasma and cell supernatant using enzyme-linked immunosorbent assay (ELISA), while the expression levels of p- ERK1/2, p-JNK, and p-p38 MAPK were assessed in the myocardium and H9c2 cells via western blot analysis. Intragastric administration of ART at a dosage of 35 mg/kg/d or over mitigated the early-stage cardiac hypertrophy induced by ISO in rats led to a reduction in left ventricular posterior wall diastolic thickness, interventricular septal thickness at diastole, lowered ANP and BNP levels, as well as a decrease in HW/tail length and HW/BW ratio. In vitro studies demonstrated that ART at a concentration of 100 μM inhibited ISO-mediated hypertrophy of H9c2 cells. The ISO group showed a higher p-ERK/GAPDH ratio and p-p38 MAPK/GAPDH ratio than the control group both in vivo and in vitro. Although the p-JNK/GAPDH ratio was increased in the ISO group, there was no statistical difference. The p-ERK/GAPDH and p-p38/GAPDH ratios were significantly lower in the ART group than in the ISO group. The mechanism of ART against cardiac hypertrophy was related to inhibition of the ERK1/2 and p38 MAPK signaling pathways.

Melatonin enhances captopril mediated cardioprotective effects and improves mitochondrial dynamics in male Wistar rats with chronic heart failure

Mitochondrial dysfunction is a recent emerging research scope that proved to be involved in many cardiovascular diseases culminating in chronic heart failure (CHF), which remains one of the primary causes of morbidity and mortality. This study investigated the added cardio-protective effects of exogenous melatonin administration to conventional captopril therapy in isoproterenol (ISO) exposed rats with CHF. Five groups of Wistar rats were recruited; (I): Control group, (II): (ISO group), (III): (ISO + captopril group), (IV): (ISO + melatonin group) and (V): (ISO + melatonin/captopril group). Cardiac function parameters and some oxidant, inflammatory and fibrotic markers were investigated. Moreover; mRNA expression of mitochondrial mitophagy [parkin & PTEN induced kinase 1 (PINK1)], biogenesis [Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)], fusion [mitofusin 2 (Mfn2)] and fission [dynamin-related protein 1 (DRP-1)] parameters in rat’s myocardium were evaluated. Rats’ myocardium was histo-pathologically and immunohistochemically evaluated for Beclin1 and Sirt3 expression. The present study revealed that captopril and melatonin ameliorated cardiac injury, oxidative stress biomarkers, and pro-inflammatory cytokines in ISO-exposed rats. These protective effects could be attributed to mitochondrial dynamic proteins control (i.e. enhanced the mRNA expression of parkin, PINK1, PGC-1α and Mfn2, while reduced DRP-1 mRNA expression). Also, Beclin1 and Sirt3 cardiac immunoreactivity were improved. Combined captopril and melatonin therapy showed a better response than either agent alone. Melatonin enhanced myocardial mitochondrial dynamics and Sirt3 expression in CHF rats and may represent a promising upcoming therapy added to conventional heart failure treatment.

Therapeutic effects of the combination of moderate-intensity endurance training and MitoQ supplementation in rats with isoproterenol-induced myocardial injury: The role of mitochondrial fusion, fission, and mitophagy

IntroductionMitochondrial dysfunction causes myocardial disease. This study investigated the effects of MitoQ alone and in combination with moderate-intensity endurance training (EX) on cardiac function and content and mRNA expression of several proteins involved in mitochondrial quality control in isoproterenol (ISO)-induced heart injuries MethodsSeven groups of CTL, ISO, ISO-EX, ISO-MitoQ-125, ISO-MitoQ-250, ISO-EX+MitoQ-125, and ISO-EX+MitoQ-250 were assigned. Rats were trained on a treadmill, and the MitoQ groups received MitoQ in drinking water for 8 weeks, starting one week after the induction of heart injury. Arterial pressure and cardiac function indices, mRNA expression, protein content, oxidant and antioxidant markers, fibrosis, and histopathological changes were assessed by physiograph, Real-Time PCR, immunofluorescence, calorimetry, Masson’s trichrome, and H&E staining, respectively. ResultsThe impacts of MitoQ-125, EX+MitoQ-125, and EX+MitoQ-250 on arterial pressure and left ventricular systolic pressure were higher than MitoQ-250 or EX alone. ± dp/dt max were higher in ISO-EX+MitoQ-125 and ISO-EX+MitoQ-250 than ISO-MitoQ-125 and ISO-MitoQ-250 groups, respectively. Histopathological scores and fibrosis decreased in ISO-EX, ISO-MitoQ-125, ISO-EX+MitoQ-125, and ISO-EX+MitoQ-250 groups. The restoration of MFN2, PINK-1, and FIS-1 changes was higher in ISO-EX+MitoQ-125 and ISO-EX+MitoQ-250 than ISO-EX, ISO-MitoQ-125 and ISO-MitoQ-250 groups. The expression of MFN2 and PINK-1 was lower in ISO-MitoQ-125 and ISO-EX+MitoQ-125 than ISO and CTL groups. The expression of FIS-1 in ISO-EX and ISO-EX+MitoQ-250 increased compared to CTL and ISO groups. MDA decreased in ISO-MitoQ-125 and ISO-EX+MitoQ-125 groups. ConclusionExercise and MitoQ combination have additive effects on cardiac function by modulating cardiac mitochondria quality. This study provided a possible therapy to treat heart injuries.

Investigation of the effect of thymoquinone on kidney damage in isoproterenol-induced myocardial infarction in rats and cardiorenal interactions

This study aimed to determine whether thymoquinone has any protective effects on renal tissue after an isoproterenol-induced myocardial infarction (MI). Experimental groups were formed as 4 groups (n=8). Control group (C). Thymoquinone group (THQ), 20 mg/kg single dose intragastric (i.g.) daily for seven days. Isoproterenol group (ISO) was administered 100 mg/kg intraperitoneally in two doses on days 7 and 8 of the experiment. Thymoquinone+Isoproterenol group (THQ+ISO), THQ 20 mg/kg i.g. was administered once a day for seven days. In addition, two doses of ISO 100 mg/kg i.p. were administered on the seventh and eighth days. Kidney tissues were evaluated histopathologically. Kidney tissues were evaluated histopathologically. Tumour necrosis factor alpha(TNF-α) and alpha Smooth Muscle Actin(α-SMA) immunoreactivity density changes were determined by immunohistochemistry. Glutathione(GST), Glutathione S-transferases(GSTs) and Interleukin-6(IL-6) levels were evaluated by ELISA method. Isoproterenol injection caused severe histopathological changes on kidney tissue. Also TNF-α and α-SMA levels were found to be higher in groups where ISO was administered. THQ could be effective on kidney tissue to partially correct these histopathological damages, by decreasing fibrosis and inflammation. This study shows that treatment with THQ is effective in preventing kidney damage caused by ISO-induced MI. We think that THQ as a supplementary food will be effective to prevent kidney damage.

Study on the Specific Expression of Infrared Radiation Temperature on the Body Surface of Acupoint in Rats with Chronic Myocardial Ischemic Injury.

Infrared thermal imaging technology was used to observe the changes in infrared radiation temperature at acupoints in rats caused by chronic myocardial ischemia injury. This study aims to compare the difference of body surface infrared radiation temperature information of three groups of acupoints: bilateral Neiguan (PC6), bilateral Yanglingquan (GB33), and bilateral Sham Acupoints (SA) in the pathological state of myocardial ischemia injury, and to explore the relationship between acupoints and viscera state. SPF adult Wistar male rats (n = 20) were randomly divided into a control (CTL; n = 10) and an isoproterenol group (ISO; n = 10). Chronic myocardial injury was induced in rats by subcutaneous injection of isoproterenol hydrochloride for 14 d. On the second day after the establishment of the model, the serum levels of cardiac troponin (cTnI) and creatine kinase isoenzyme (CK-MB) were measured by enzyme-linked immunosorbent assay (ELISA). The morphological changes of the myocardial tissue in the two groups were observed by hematoxylin-eosin (HE) staining and their pathological scores were evaluated, which was then used to determine the myocardial ischemic injury. Two days before and after the establishment of the model, the electrocardiograms (ECG) of the two groups of rats were recorded by the (ECG) data acquisition system, and the infrared thermal imaging platform was used to detect the temperature of the six acupoints. 1. After subcutaneous injection of isoproterenol hydrochloride for 14 days, the ST segment of the ECG decreased in the ISO group compared with that of the CTL group; 2. Myocardial tissue injury was serious in the ISO group compared to the CTL group; 3. Serum cTn-I and CK-MB were significantly increased (P <0 01) in the ISO group, compared to that in the CTL group; 4. The infrared radiation temperature on the body surface of bilateral Neiguan (PC6) acupoints decreased significantly in the ISO group, compared to that of the CTL group. Infrared thermal imaging technology can be used to detect the changes in the energy state of acupoints. Chronic myocardial ischemic injury can cause a decrease in IR temperature on the body surface of bilateral Neiguan (PC6) acupoints, suggesting that visceral diseases can lead to changes in the energy metabolism of acupoints.

Naringenin suppresses NLRP3 inflammasome activation via the mRNA-208a signaling pathway in isoproterenol-induced myocardial infarction

Objective: To investigate the cardioprotective effect of naringenin against isoproterenol (ISO)-induced cardiotoxicity in rats. Methods: Rats were divided into five groups: the normal group, the ISO group (85 mg/kg b.w.); the ISO+naringenin (50 mg/kg b.w.) group, the ISO+naringenin (100 mg/kg b.w.) group and the ISO+propranolol (10 mg/kg b.w.) group. Plasma creatine kinase-MB (CK-MB), cardiac troponin T, lactate dehydrogenase, brain natriuretic peptide (BNP), and IL-10, as well as cardiac transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF) and malondialdehyde (MDA) were examined. In addition, NLRP3 and mRNA-208a expressions were evaluated by RT-PCR analysis. Histopathological examination was also performed to assess cardiac damages. Results: Naringenin treatment significantly decreased plasma lactate dehydrogenase, CK-MB, cardiac troponin T, BNP, and IL-10, as well as cardiac TGF-β1, VEGF, and MDA while increasing p-Akt and superoxide dismutase in ISO-administered rats. It also reduced NLRP3 and mRNA-208a gene expression levels. Furthermore, naringenin improved ISO-induced cardiac damage. Conclusions: Naringenin attenuates myocardial dysfunction in ISO-treated rats by decreasing oxidative stress and increasing cardiac endogenous antioxidant system, which may be modulated partly by improvement of NLRP3 and mRNA-208a gene expression.