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Pathological cardiac hypertrophy serves as a significant foundation for cardiac dysfunction and heart failure. Recently, growing evidence has revealed that microRNAs (miRNAs) play multiple roles in biological processes and participate in cardiovascular diseases. In the present research, we investigate the impact of miRNA-34c-5p on cardiac hypertrophy and the mechanism involved. The expression of miR-34c-5p was proved to be elevated in heart tissues from isoprenaline (ISO)-infused mice. ISO also promoted miR-34c-5p level in primary cultures of neonatal rat cardiomyocytes (NRCMs). Transfection with miR-34c-5p mimic enhanced cell surface area and expression levels of foetal-type genes atrial natriuretic factor (Anf) and β-myosin heavy chain (β-Mhc) in NRCMs. In contrast, treatment with miR-34c-5p inhibitor attenuated ISO-induced hypertrophic responses. Enforced expression of miR-34c-5p by tail intravenous injection of its agomir led to cardiac dysfunction and hypertrophy in mice, whereas inhibiting miR-34c-5p by specific antagomir could protect the animals against ISO-triggered hypertrophic abnormalities. Mechanistically, miR-34c-5p suppressed autophagic flux in cardiomyocytes, which contributed to the development of hypertrophy. Furthermore, the autophagy-related gene 4B (ATG4B) was identified as a direct target of miR-34c-5p, and miR-34c-5p was certified to interact with 3' untranslated region of Atg4b mRNA by dual-luciferase reporter assay. miR-34c-5p reduced the expression of ATG4B, thereby resulting in decreased autophagy activity and induction of hypertrophy. Inhibition of miR-34c-5p abolished the detrimental effects of ISO by restoring ATG4B and increasing autophagy. In conclusion, our findings illuminate that miR-34c-5p participates in ISO-induced cardiac hypertrophy, at least partly through suppressing ATG4B and autophagy. It suggests that regulation of miR-34c-5p may offer a new way for handling hypertrophy-related cardiac dysfunction.
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Themorbidity and mortality of heart failure (HF) are increasing with the rise of life expectancy in recent years, which emphasize the early diagnosis and optimal treatment. Biomarkers for HF play an important role in the prediction, diagnosis, prognosis and treatment guiding of HF. Natriuretic peptide (NP) is the most widely used biomarkers for HF. However, NP is not an ideal biomarker due to low specificity. Recently, more biomarkers were found to be valuable on the basis of NP in the evaluation of HF. This consensus summarized the biomarkers for HF according to latest clinical guidelines, expert statements and clinical trials. It is meant to provide reference in the application ofbiomarkers for HF.
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Ghrelin is a novel growth hormone-releasing peptide administered to treat myocardial infarction (MI). However, the underlying mechanism of its protective effects against MI remains unclear. A total of sixty healthy Sprague Dawley male rats were included. The first one is the sham-operated control group were the rats that underwent the same surgical used to induce MI but without tying the left anterior descending coronary artery (LAD) and received normal saline (0.5 ml) as vehicle; the second MI model group were rats with LAD ligation and received normal saline (0. 5 ml) and the third one is MI+ghrelin group were rats that were exposed to surgery to induce MI but received ghrelin (100 µ/kg, orally, 2x/day). At the end of the experiment after 21 days post-MI, rats were sacrificed and processed for ultrastructural demonstration. Our experiment showed that ghrelin inhibited cardiomyocyte apoptosis. Concomitant administration of ghrelin with MI treated rats of this study appeared to show a considerable protection of the atrial tissues. This study revealed that the sarcoplasm was occupied by normal myofibrils with clear striations and others appeared with minor disruption. Normal distribution of atrionatriuretic factor (ANF) granules and well preserved mitochondrial integrity (preserved cristae, normal size and shape), nucleus chromatin arrangement and striated pattern of clear bands (Z and H) compared to the MI group. Intact intercalated disc with clear identification of fully formed fascia adherence and desmosomes with a reconstruction of gap junction (nexus) was also noticed. Atrial myocytes after myocardial infarction is often associated with subsequent heart failure, which could lead to a fatal outcome. In a rat model of experimental myocardial infarction, peripheral ghrelin administration attenuated myocyte dysfunction, well-preserved desmosome, adherent and gap junction of the intercalated disc and normally distributed ANF granules.
La grelina es un nuevo péptido liberador de hormona de crecimiento administrado para tratar el infarto de miocardio (IM). Sin embargo, el mecanismo subyacente de sus efectos protectores contra el IM aún no se conocen. Se incluyeron un total de 60 ratas macho Sprague Dawley saludables. En el grupo control se incluyeron ratas que fueron sometidas a una cirugía utilizada para inducir el IM, pero sin ligar la arteria coronaria descendente anterior izquierda (ACDAI) y recibieron suero fisiológico normal (0,5 ml) como vehículo; el segundo grupo modelo de IM fueron ratas con ligadura de ACDAI y recibieron suero fisiológico normal (0,5 ml); el tercer grupo estuvo formado por ratas con IM + grelina, expuestas a la cirugía para inducir IM pero luego recibieron grelina (100 m/kg, oralmente, 2x/día). Al final del experimento, 21 días después del infarto de miocardio, los animales fueron sacrificados y procesados para el estudio ultraestructural. Nuestro experimento mostró que la grelina inhibe la apoptosis de los cardiomiocitos. La administración concomitante de grelina en ratas con IM parece indicar una protección considerable de los tejidos atriales. Además, el estudio reveló que el sarcoplasma estaba ocupado por miofibrillas normales con estriaciones claras y otras con una alteración menor. Se encontró una distribución normal de los gránulos del factor natriurético atrial (FNA) e integridad mitocondrial bien conservada (crestas conservadas, tamaño y forma normales), disposición de la cromatina del núcleo y patrón estriado de bandas claras (Z y H) en comparación con el grupo IM. También se observó un disco intercalado intacto con una clara identificación de la adherencia de la fascia completamente formada y desmosomas con una reconstrucción de la unión gap (nexo). Los miocitos atriales, después de un infarto de miocardio, a menudo se asocian con insuficiencia cardíaca posterior, que podría conducir a un desenlace fatal. En un modelo de rata de infarto de miocardio experimental, la administración de grelina periférica atenuó la disfunción de miocitos, con conservación del desmosoma, adherencia y unión de la brecha del disco intercalado y una distribución normal de los los gránulos de FNA.
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Animals , Male , Rats , Atrial Natriuretic Factor/metabolism , Peptide Hormones/metabolism , Myocardial Infarction/metabolism , Atrial Natriuretic Factor/ultrastructure , Rats, Sprague-Dawley , Microscopy, Electron, Transmission , Disease Models, Animal , GhrelinABSTRACT
Corin is a kind of type II transmembrane serine protease.Recently, its application in cardiovascular field like hypertension, heart failure, coronary heart disease (CHD) etc.have received more and more attention.The present article made following review on research progress of Corin in cardiovascular field.
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Objective To investigate the effect of exogenous atrial natriuretic peptide on airway inflammation in allergic asthma mice model and its mechanism.Methods A total of 48 SPF 48 BALBc mice were selected and randomly divided into the normal group (equal quantity normal saline intervention),model group (equal quantity normal saline intervention),experimental group A (exogenous atrial natriuretic peptide 0.5 μg/g) and experimental group B(exogenous atrial natriuretic peptide 0.5 μg/g-+-A71915).The model group,experimental group A and B were given the corresponding treatment measures after successfully constructing the model,at 24 after the last provocation test,serum and bronchoalveolar lavage fluid in each group were collected for detecting inflammation factors.The HE staining was used to observe the pathological changes of lung tissue,the expression level of GATA3 protein in lung tissue was detected by Western blot technology.Results The blood EOS,lymphocyte and neutrophil ratio in the model group were higher than those in the normal group (P＜0.05),which in the experimental group A were higher than those in the model group and experimental group B (P＜0.05);bronchoalveolar lavage fluid EOS,lymphocytes,neutrophil ratio,IL-6,TNF-α levels in the model group were higher than those in the normal group (P＜0.05),alveolar lavage fluid EOS,lymphocyte,neutrophil count,IL-6 and TNF-α levels in the experimental group A were higher than those in the model group and experimental group B (P＜0.05);the expression level of GATA3 protein in lung tissue of the model group was higher than that in the normal group(P＜0.05),the expression level of lung tissue GATA3 protein in the experimental group A was higher than that in the model group and experimental group B (P＜0.05).Conclusion Exogenous atrial natriuretic peptide can further aggravate airway inflammation reaction in allergic asthma mice model,which is related to the activation of inflammatory cells,the release of inflammatory cytokines and the increase of GATA3 protein expression in lung tissue.
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RESUMO Objetivo: Avaliar a presença de hiponatremia e natriurese, bem como suas associações com o fator natriurético atrial em pacientes de neurocirurgia. Métodos: Foram incluídos 30 pacientes submetidos à ressecção de tumor intracraniano e à clipagem de aneurisma cerebral. Os níveis plasmáticos e urinários de fator natriurético atrial foram medidos durante os períodos pré e pós-operatório. Resultados: Hiponatremia esteve presente em 63,33% dos pacientes, particularmente no primeiro dia pós-operatório. Observou-se natriurese em 93,33% dos pacientes, principalmente no segundo dia pós-operatório. Os níveis plasmáticos de fator natriurético atrial estavam aumentados em 92,60% dos pacientes em pelo menos um dos dias pós-operatórios, mas não houve associação estatisticamente significante entre fator natriurético atrial e sódio plasmático, e entre fator natriurético atrial e sódio urinário. Conclusão: Após neurocirurgia, na maior parte dos pacientes, estiveram presentes hiponatremia e natriurese; contudo, o fator natriurético atrial não pôde ser considerado diretamente responsável por tais alterações nos pacientes neurocirúrgicos. Provavelmente, há o envolvimento de outros fatores natriuréticos.
ABSTRACT Objective: To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. Methods: The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. Results: Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. Conclusion: Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved.
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Humans , Male , Female , Adult , Atrial Natriuretic Factor/blood , Neurosurgical Procedures/methods , Hyponatremia/epidemiology , Natriuresis/physiology , Postoperative Period , Sodium/urine , Brain Neoplasms/surgery , Intracranial Aneurysm/surgery , Prospective Studies , Preoperative Period , Middle AgedABSTRACT
Objective The aim of the present study was to monitor the plasma levels of atrial natriuretic peptide(ANP) in patients accepting minimally invasive ablation.Methods The demographic and clinical data were collected from 26 consecutive patients with paroxysmal atrial fibrillation.Two milliliter of peripheral blood was harvested before operation,7 days and 3 months post-operation followed by ANP assay using ELISA kit.The repeated measurements were performed for each sample and One-way ANOVA was used for statistical analysis.Results Before operation,the ANP levels in plasma was (2.86 ± 1.47) pg/ml.No significant changes of this ANP levels were observed 7 days and 3 months after operation,which were(2.83 ± 1.08) pg/ml and(2.75 ±0.87) pg/ml,respectively.The Pvalue of sphericity Mauchly test was 0.008 for repeated measurements and for correction coefficient,P =0.801.Conclusion These findings suggest that the minimally invasive ablation and left appendage excision in patients with atrial fibrillation has no significant effect on atrial ANP secretion.
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Objective To evaluate the predictive value of serum macrophage migration inhibitory factor (MIF) for myocardial depression in severe sepsis patients.Methods Taken prospective study method,42 cases of severe sepsis patients were enrolled from December 2011 to June 2013.The patients were monitored by PICCO system after informing consent into ICU day,and given the corresponding treatment.According to the hemodynamic parameters were divided into two groups,myocardial depression group:cardiac index ＜ 3 L/(min· m2) and global end diastolic volume index ＞ 800 ml/m2,the remaining were in non myocardial depression group,and the patients were divided into survival group and death group according to 28-d mortality.Hemodynamic parameters and serum MIF,B-type natriuretic peptide (BNP),cardiac troponin Ⅰ (cTnI) level at the 1st,3rd,Sth day after admission.Results Fortty-two severe sepsis patients,non myocardial depression in 22 cases (non myocardial depression group),myocardial suppression in 20 cases (myocardial depression group).At 28 d,20 patients of survival (survival group),22 patients of death (death group).The serum MIF in death group was higher than that in survival group at the 1st,3rd,5th day (P ＜ 0.01) ; BNP and cTnI at the 1st day in two groups had no statistical significance (P ＞0.05),BNP and cTnI at the 3rd,5th day in death group was higher than that in survival group(P ＜ 0.01).The serum MIF at each time point in myocardial depression group was higher than that in non myocardial depression group [survival:8.70(3.53,16.80) μ g/L vs.1.20(0.80,1.77) μ g/L,2.30(1.33,8.40) μ g/L vs.0.60 (0.60,0.99) μg/L,0.50 (0.31,2.50) μg/Lvs.0.16 (0.15,0.20) μg/L;death:11.43(8.10,17.16) μ g/L vs.2.30(1.96,3.69) μ g/L,9.70(6.55,14.65) μ g/L vs.1.90(1.88,5.27) μ g/L,7.50(5.15,14.20)μ g/L vs.2.40(0.80,8.46) μ g/L] (P ＜ 0.05).The serum MIF of death patients in two groups was higher than that of survival patients (P ＜ 0.05).MIF at the 5th day had biggest prediction value,AUC was 0.952,when the cut-off point of 0.65 μg/L,the sensitivity was 100％ (22/22) and specificity was 85％ (17/20).Multivariable Logistic regression analysis results showed that only APACHE Ⅱ scores was the independent risk factor for 28-d mortality (P ＜ 0.01),while MIF couldn' t independent forecast 28-d mortality (P ＞ 0.05).Conclusions Elevation of serum MIF prompts severe sepsis patient with poor outcome,and dynamic changes of MIF is helpful to evaluate the prognosis and severity of severe sepsis patients with myocardial depression,but MIF is not an independent risk factor for predicting 28-d mortality.
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Objective To explore the correlation between N-terminal pro-brain natriuretic peptide ( NT-porB-NP) and D-dimer in coronary artery disease patients with type 2 diabetes .Methods 50 coronary heart disease patients with type 2 diabetes were selected as the study group ,and 30 healthy subjects at the same period were select-ed as the healthy control group .The serum levels of NT-porBNP and D-dimer were detected in two groups ,and the cor-relation between NT-porBNP and D-dimer was analyzed .Results The serum D-dimer and NT-porBNP levels in the study group were significantly higher than those in the control group [(2.43 ±0.58)mg/L vs (0.26 ±0.13)mg/L, (1 487.8 ±201.5)pg/L vs (83.3 ±21.4)pg/L](t=21.34,32.12,all P<0.05).The D-dimer level was positively correlated with the NT-porBNP level (r=0.564,P<0.05).Conclusion In coronary heart disease patients with type 2 diabetes ,the serum levels of D-dimer and NT-proBNP are high and closely related .
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B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) have been widely used in the diagnosis and management of heart failure (HF).In recent years,some new biomarkers emerged in different pathophysiological procedure of HF development,such as myocardial injury,myocarditis,myocardial remodeling,etc.Mid-regional proatrial natriuretic peptide (MR-proANP),one of the most deeply researched and widely used emerging biomarkers,has been reported that it has the same value in HF diagnosis and is better in HF prognosis,compared with BNP and NT-proBNP.MR-proANP could also be an independent factor in HF diagnosis and prognosis.However,further research is still needed in risk assessment of cardiovascular event.
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OBJETIVO: Avaliar o prognóstico do tromboembolismo pulmonar usando o ecocardiograma com Doppler tecidual e o peptídeo atrial natriurético. MÉTODOS: Pacientes com idade acima de 18 anos foram avaliados pelo ecocardiograma bidimensional e Doppler tecidual para medidas das velocidades miocárdicas (s'), strain e índice de performance miocárdica do ventrículo direito até 24 horas da confirmação diagnóstica do tromboembolismo pulmonar (tomografia/ cintilografia), sendo também o peptídeo atrial natriurético obtido até 24 horas. A influência das variáveis na mortalidade até 1 ano foi testada pela regressão de Cox. RESULTADOS: Dos 118 pacientes estudados, 100 foram incluídos, sendo 60 homens, com idade de 55±17 anos. Pelo ecocardiograma bidimensional, 28% dos pacientes apresentavam disfunção do ventrículo direito. As medidas da onda s', strain e deslocamento estiveram diminuídas para tais pacientes, que apresentavam, ainda, índice de performance miocárdica e pressão sistólica pulmonar aumentados. O peptídeo atrial natriurético médio foi de 66±111pg/mL, sendo 136±146pg/mL para pacientes com disfunção do ventrículo direito. A mortalidade foi 11% e pela análise univariada, relacionada à idade, neoplasia e peptídeo atrial natriurético. Entre as variáveis ecocardiográficas, somente a onda s' do Doppler tecidual e a pressão pulmonar associaram-se à maior mortalidade. Pela análise multivariada, entretanto, a presença de neoplasia foi o único preditor de óbito. CONCLUSÃO: Velocidades miocárdicas diminuídas e peptídeo atrial natriurético elevado estão associados a pior prognóstico em pacientes com tromboembolismo pulmonar, mas, nessa população, somente a presença de neoplasia foi capaz de predizer a mortalidade de maneira independente.
OBJECTIVE: To assess prognosis of pulmonary thromboembolism using tissue Doppler echocardiography and brain natriuretic peptide. METHODS: Patients aged over 18 years were evaluated within 24 hours of confirmed diagnosis (chest tomography/pulmonary scintigraphy) of pulmonary embolism using two-dimensional echocardiography and tissue Doppler for right ventricular systolic (s') velocities, strain, tissue tracking and myocardial performance index. Plasma brain natriuretic peptide was also obtained within 24 hour. The influence of echocardiographic and clinical variables on mortality was examined (up to 12 months) using Cox regression analysis. RESULTS: Out of 118 patients, 100 patients were included in the study (60 males, aged 55±17 years). Right ventricular dysfunction was observed in 28% using two-dimensional echocardiography. Tissue Doppler right ventricular variables (s' velocities, tissue tracking and strain) were decreased only for patients with right ventricular dysfunction, whereas myocardial performance index and systolic pulmonary artery pressure were increased. Mean brain natriuretic peptide value was 66±111pg/mL, also increased in patients with right ventricular dysfunction (136±146pg/mL). Mortality was 11% and related to age, malignancy and brain natriuretic peptide levels. The only echocardiographic variables capable of predicting events by univariate analysis were pulmonary pressure and right ventricular s' velocity. However, multivariate analysis showed only malignancy to predict mortality in this group. CONCLUSION: Lower tissue Doppler systolic velocities and elevated brain natriuretic peptide levels are associated with poorer prognosis in patients with pulmonary thromboembolism; but only malignancy emerged as an independent predictor of mortality.
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Atrial Natriuretic Factor , Echocardiography, Doppler/methods , Hypertension, Pulmonary , Pulmonary EmbolismABSTRACT
Objective To explore the detection significance of brain natriuretic peptide in peripheral blood of patients with coronary heart disease(CHD).Methods 260 patients with CHD were selected and divided into 95 cases of stable angina pectoris(SAP) group,85 cases of unstable angina pectoris(UAP) group and 80 cases of acute myocardial infarction(AMI) group according to angiographic and clinical diagnosis.Another 80 cases of healthy people which were taken medical examination were selected as the healthy control group.The peripheral blood plasma brain natriuretic peptide concentration of the study objects were detected,and the severity of coronary lesions was quantified by the coronary Gensini score.Results The peripheral blood brain natriuretic peptide average concentration of UAP group and AMI group was (498.00 ± 87.00) ng/L and (936.00 ± 102.25) ng/L,respectively,which were significantly higher than that of the SAP group [(213.46 ± 98.35) ng/L] and the control group [(97.63 ±20.07) ng/L] (t =8.78,12.01,6.26,2.38,all P ＜ 0.05).The peripheral blood brain natriuretic peptide concentration of patients with Gensini score≥20 points was significantly higher than that of the patients with Gensini score ＜20points(P ＜ 0.05).Conclusion The peripheral blood brain natriuretic peptide concentration of patients with CHD is correlated with coronary plaque stabilization and lesion severity.
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Objective: To investigate the protection of Angelica sinensis extract on the left ventricular hypertrophy (LVH) of rats and explore the possible mechanisms. Methods: Male SD rats were randomly divided into Sham, model, and low-, mid-, and high-dose A. sinensis extract (25, 50, and 100 mg/kg), and L-arginine (200 mg/kg) positive control groups. Except for Sham group, the rats with LVH were induced by abdominal aorta coarctation and were administered from the next day after surgery once daily for consecutive 21 d. Changes of cardiac hypertrophy parameters and hemodynamic indexes of rats were observed. Left ventricular myocardial fiber diameter (MD) was determined. Electron microscopy was used to observe the ultrastructure of myocardial tissue. RT-PCR was used to determine the mRNA expression of atrial natriuretic factor (ANF) and calcineurin phosphatase (CaN). Western blotting was used to determine the expression of α-subunit of calcineurin phosphatase (CnA). Results: Compared with Sham group, the left ventricular hypertrophy index (LVHI), the left ventricular weight/right ventricular weight (LVW/RVW), and MD were remarkably increased, the expression of ANF, CaN mRNA, and CnA protein was obviously elevated. A. sinensis extract could remarkably decrease LVHI, tend to or significantly decrease LVW/RVW, improve the indicators of systolic and diastolic function, and down-regulate the expression of ANF, CaN mRNA and CnA protein. Conclusion: A. sinensis extract has the protection against LVH induced by abdominal aorta coarctation in rats, and the mechanism may be related to its inhibitory effects on CaN signaling pathway.
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Objective To observe the effects of trimetazidine (TMZ) on the cardiac function and neurohormonal of heart failure model in rats.Methods Partially banding abdominal aortic artery to achieve congestive heart failure rats model.Interventricular septum thickness(IVST),left ventricular posterior wall thickness(LVPWT),left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter (LVESD),left ventricular ejection fraction(LVEF) and shortening fraction(FS) were measured by echocardiogram,Pathological changes of myocardial cells was observed,B-type natriuretic peptide (BNP)、C-type natriuretic peptide receptor (NPRC),atrial natriuretic peptide (ANP),myosin heavy chain (β-MHC) and angiotensinl (AT1) were measured by Real-Time PCR,superoxide dismutase (SOD) was measured by immunohistochemistry method.Results Trimetazidine treatment of the high-dose group and the model group compare IVST LVPWT,LVESD,LVEDD were (0.63 ± 0.05) mn,(0.73 ± 0.06) mm,(0.73 ±0.05)mm,(0.87 ±0.06)mm and (1.07 ±0.06)mm,(1.13 ±0.06) mm,(0.93 ±0.06)mm,(1.33 ±0.06) mm,was significantly reduced (P ＜ 0.05),LVEF,FS increased to (27.75 ± 1.83) ％,(11.44 ± 0.76) ％ and (11.78 ±0.56)％,(4.27 ± 0.22)％ (P ＜ 0.01),Myocardial cell structure were remarkably improved.The expression of BNP,ANP,NPRC,ATI,β-MHC were remarkably decreased.The expression of SOD was elevated.Conclusion TMZ treatment group can improve the secretion of neurohormonal of heart failure model in rats,and also obviously improve the cardiac contractility.
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Objective To explore the change in plasma B-type natriuretic peptide (BNP) concentration and its potential influencing factors in elderly patients with hypertension.Methods A total of 137 patients with hypertension [75 males,62 females,aged (78.3±7.5) years] were enrolled in this study.Patients were divided into 3 groups:simple hypertension (SH) group (n=36),hypertension combined with cardiac structural changes (HCSC) group (n=31),and hypertension combined with systolic heart failure (HHF) group (n=70).Plasma BNP concentration was measured by immunofluorescence antibody method.Cardiac structure and function parameters in patients were detected by echocardiography within 24-48 hours after taking blood samples.Data was analyzed by SPSS 16.0.Results There were significant differences in the value of lgBNP among HHF,HCSC and SH groups (2.8±0.4,2.0±0.5,1.9±0.5,respectively,F 61.69,P＜0.05).Multiplelinear regression analysis showed that left atrial diameter (LAD),left ventricular ejection fraction (LVEF),age,LVMI (left ventricular mass index) and pulse pressure (PP) were the five effective variables of the lgBNP (F=58.69,P＜0.05) in HCSD group and SH group.The regression equation was:lgBNP=0.010X1 +0.007X2-0.054X3 +0.049X1 +0.013X5 +2.635 (X1 represented as PP,X2 as age,X3 as LVEF,X4 as LAD and X5 as LVMI).The standardized regression coefficient of X1 to X5 was0.446,0.235,-0.621,0.574 and 0.457,respectively.The value of lgBNP in patients with normal contractile function was higher in patients with late diastolic mitral flow velocity ratio (E/A)＜1 than in those with E/A＞1 (2.42±0.35 vs.2.25±0.16,t=0.94,P＜0.05).Conclusions The plasma BNP concentration is negatively correlated with LVEF and positively correlated with LAD,PP,age and LVMI in elderly patients with hypertension.The effect degree from great to little in line was LVEF,LAD,LVMI,PP and age.In addition,there is a negative correlation between plasma BNP concentration and E/A ratio in patients with normal contractile function.
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Objective To observe the effects of different posture on hemodynamics and plasma atrial natriuretic polypeptide(ANP) during laparoscopic surgery. Methods Forty patients who scheduled for elective laparoscopic surgery under general anesthesia were allocated into two groups according to their posture during laparoscopic surgery,20 cases for each group. In group A, the patients were arranged in a head-down tilt position, in group B, the patients were arranged in a head-up tilt position systolic blood pressure (SBP),diastolic blood pressure (DBP),central venous pressure (CVP) and electro cardio gram (ECC) were monitored continuously. Blood samples were taken from central venous at four time points of prepneumoperitoneum(T1), 10 minutes after that(T2) and 20 mintues(T3) when the patients were arranged at the different operation-needed position with a stable pneumoperitoneum pressure of 14 mm Hg (1 mm Hg = 0.133 kPa),and at 5 minutes (T4) after deflation of pneumoperitoneum when the patients returned to supine position. The plasma ANP was assessed by radioimmunoassay. Results In group A,the CVP at T2 and T3 [(14.45 ±2.72),(14.20 ±2.46) mm Hg] was significantly higher than that at T1 [(6.05 ±1.76) mm Hg] (P<0.01), in group B,the CVP at T2 and T3 [(8.90±1.27),(9.02 ±0.47) mm Hg] was significantly higher than that at T1[(6.30 ±1.34) mm Hg](P< 0.01) ,with a higher level in group A than those in group B at the same time point during pneumoperitoneum(P< 0.01). The ANP level in group A was higher at T2 than that at T1, and there was significantly higher at T3 than that at T1 (P < 0.05). But the ANP level was significantly higher in group A than that in group B at the same time points of T2 and T3 (P < 0.05). Conclusion The posture may have obvious effect on CVP and plasma ANP level during laparoscopic surgery.
ABSTRACT
Durante la hipertensión arterial, las interacciones entre las sobrecargas de presión y volumen conducen a diferentes patrones de hipertrofia cardíaca y a un aumento de los péptidos natriuréticos (PN). Los perfiles de síntesis y secreción de ANP y BNP se han investigado en modelos de hipertensión arterial. Sin embargo, aún no se ha estudiado su evolución diferencial durante períodos agudos y crónicos de la hipertrofia cardíaca producida por sobrecarga de presión. Por este motivo estudiamos ratas Sprague-Dawley con el modelo 1 riñón-1 clip a las 2, 4, 6 y 12 semanas, correlacionando la evolución de dichos perfiles con la hipertrofia cardíaca y la hipertensión arterial. Observamos una correlación positiva entre la elevación de la presión arterial y el grado de hipertrofia cardíaca, presentando ambos parámetros un incremento dependiente del tiempo a partir de las 2 semanas. La expresión del BNP mostró un aumento precoz a las 2 semanas de tratamiento, mientras que el ANP se incrementó significativamente a las 6 semanas. No obstante, la expresión del ANP aumentó en forma gradual, lo que permitió su correlación con la hipertrofia y la hipertensión. En estadios tempranos del desarrollo de la hipertrofia producida por el modelo renovascular, la expresión de los PN respondería en forma diferencial, incrementándose en forma precoz el BNP. Con la evolución de la hipertrofia, la expresión del BNP deja de ser específica y el aumento de ambos PN pasa a depender y a correlacionarse con el grado de evolución de la hipertrofia cardíaca.
The interactions between pressure and volume overload that occur in hypertension lead to different patterns of cardiac hypertrophy and to increase natriuretic peptides (NPs) levels. The profiles of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) synthesis and secretion have been investigated in models of hypertension. However, the different evolution of these profiles during the acute and chronic periods of pressure overload-induced cardiac hypertrophy is still unknown. For this reason, we studied one-kidney, one clip model using Sprague-Dawley rats at weeks 2, 4, 6 and 12 and correlated the evolution of these profiles with cardiac hypertrophy and hypertension. We observed a positive correlation between blood pressure elevation and the degree of cardiac hypertrophy, with a time-dependent increase in both parameters from week 2. Levels of BNP expression showed an early increase after 2 weeks of treatment while ANP increased significantly after 6 weeks. Neverless, the increase in ANP expression was gradual, allowing its correlation with hypertrophy and hypertension. The NP expression has a differential response in the early stages of the development of hypertrophy induced by the renovascular model, with an early increase in BNP expression. Once hypertrophy develops, BNP expression is no longer specific and the increase of both NPs depends on and correlates with the degree of cardiac hypertrophy.
ABSTRACT
Objective To assess the effect of 5-azacytidine (5-AZ) on the expressions of atrial natriuretic peptide (ANP) and β-myosin heavy chain (β-MHC) genes in cultured rat bone marrow stromal cells (BMSCs). Methods Neonatal rat cardiomyocytes and adult rat BMSCs were isolated and cultured. BMSCs were incubated with 5-AZ and (or) myocardiocytes culture medium. RT-PCR was used to measure the expressions of cardiac ANP and β-MHC genes. Results Normally cultured rat BMSCs didn't express cardiac ANP or β-MHC. After inducing by 5-AZ, rat BMSCs expressed ANP or β-MHC. The myocardiocytes culture medium enhanced expression of β-MHC, but didn't affect the expression of ANP. Conclusions The 5-AZ induces the rat BMSCs to express either cardiac ANP or β-MHC, and the former could be enhanced by cardiomyocytes culture medium.
ABSTRACT
Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y4 receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y4 receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y2 receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y1, 2, 5 receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y3 receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y2 receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y4 and Y2 receptor differently regulate the release of atrial ANP.
Subject(s)
Animals , Rats , Arginine/analogs & derivatives , Atrial Natriuretic Factor/metabolism , Benzazepines/pharmacology , Gene Expression Regulation , Pancreatic Polypeptide/pharmacology , Peptide YY/pharmacology , Rats, Sprague-Dawley , Receptors, Neuropeptide Y/agonistsABSTRACT
Introducción El péptido natriurético auricular (ANP) y el óxido nítrico (NO) aumentan la diuresis y la natriuresis y disminuyen el tono vascular. Previamente demostramos que el NO está involucrado en el efecto hipotensor del ANP en ratas normotensas. Objetivo Estudiar el efecto del ANP sobre la presión arterial media (PAM) y el sistema del NO en ratas espontáneamente hipertensas (SHR) y Wistar Kyoto (WKY) y la participación de la isoforma inducible de la NO-sintasa (iNOS). Material y métodos Protocolo 1: los animales fueron infundidos con solución salina (0,05 ml/min) o con ANP (0,2 µg/kg/min) durante 1 hora. Se determinaron: PAM y nitritos y nitratos urinarios (NOx). Se extrajo el corazón y se determinaron la actividad, con L-[U14C]-arginina, y la expresión (Western blot) de iNOS y NOS endotelial (eNOS). Protocolo 2: luego del agregado de ANP (1 µM), cANP(4-23) (agonista NPR-C,1µM) o aminoguanidina (inhibidor de iNOS, 1 µM) se determinó la actividad de la NOS en la aurícula derecha y en el ventrículo izquierdo de SHR y WKY. Resultados La infusión con ANP disminuyó la PAM y aumentó los NOx en ambos grupos. La actividad NOS fue mayor en SHR y se incrementó con la infusión de ANP. Se observaron niveles proteicos mayores para eNOS e iNOS en SHR, que no se modificaron con ANP. La actividad basal de iNOS fue mayor en SHR. En la aurícula, el ANP sólo interactuaría con el NPR-C para activar la NOS y en el ventrículo también participarían los receptores NPR-A/B. El desarrollo y/o el mantenimiento de la hipertensión en este modelo experimental involucraría alteraciones en la interacción entre ambos sistemas, ANP y NO.
Background Atrial natriuretic peptide (ANP) and nitric oxide (NO) increase diuresis and natriuresis and reduce vascular tone. We have previously demonstrated that NO is involved in ANP hypotensive effect in normotensive rats. Objective To assess the effect of ANP on mean blood pressure (MBP) and on NO system in spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY), and the role of the inducible isoform of nitric oxide synthase (iNOS). Material and Methods Protocol 1: animals were instilled with saline solution (0.05 ml/min) or with ANP (0.2 µg/kg/min) for an hour. MBP and urinary nitrites and nitrates (NOx) were assessed. The heart was extracted and iNOS and endothelial iNOS (eNOS) activity (with L-[U14C]-arginine) and expression (Western blot) were determined. Protocol 2: after adding ANP (1 µM), cANP(4-23) (NPR-C agonist, 1µM) or aminoguanidine (iNOS inhibitor, 1 µM) NOS activity in the right atrium and left ventricle of SHR and WKY was determined. Results Instillation with ANP reduced MBP and increased NOx in both groups. NOS activity was greater in SHR, and increased with the instillation of ANP. In SHR, greater eNOS and iNOS protein levels were observed, which were not modified by ANP. iNOS basal activity was greater in SHR. In the atrium, ANP interacts only with NPR-C in order to activate NOS, and NPR-A/B receptors would also take part in the ventricle. In this experimental model, the development and maintenance of hypertension could involve alterations in the interaction between both systems, ANP and NO.