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BACKGROUND: When advanced heart failure occurs in cardiac amyloidosis, prognosis is poor. In this setting heart transplantation (HTX) is a treatment option for selected patients. We here present the results of post-transplantation outcomes in cardiac amyloidosis within the Eurotransplant area, investigating possible predictors of survival. METHODS: Of 115 patients undergoing HTX due to cardiac amyloidosis in the Eurotransplant region between November 1987 and May 2020, detailed assessment prior to transplantation was available in 85 patients. The present study was conducted in a retrospective approach. Primary endpoint was mortality after HTX. Baseline variables were entered in a Cox proportional hazards model with the primary endpoint as a dependent variable. RESULTS: Median overall survival following HTX was 6.3 years in the overall collective and the subgroup. Univariate Cox proportional hazards model revealed a significant relationship between overall survival and the transplantation period (2008 to 2020 vs 1987 to 2007; median survival 9.7 years vs 1.8 years, hazard ratio 0.45, p = 0.01). Further predictors were albumin concentration (hazard ratio 0.92, p < 0.001), and systolic blood pressure (hazard ratio 0.96, p < 0.001). The transplant period as well as albumin concentration remained significant independent predictors in the AL sub cohort in a multivariate Cox proportional hazards model. CONCLUSIONS: HTX is a viable treatment option for patients at an advanced stage of cardiac amyloidosis as overall survival after transplantation has improved in the modern age. Patients at a very advanced stage of the disease, indicated by low serum albumin and blood pressure, show worse outcomes following HTX. Optimal timing and careful patient selection may therefore be particularly important to further improve post-HTX survival in amyloidosis patients.
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Amiloidose , Insuficiência Cardíaca , Transplante de Coração , Humanos , Estudos Retrospectivos , Transplante de Coração/efeitos adversos , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/cirurgia , Amiloidose/complicações , Amiloidose/cirurgia , AlbuminasRESUMO
AIMS: Implantation of a left ventricular assist device (LVAD) is an established treatment option for patients with advanced heart failure. However, apart from its challenging medical management, it comes with serious psychological implications. Empirical evidence suggests that self-compassion, a self-regulation strategy for countering negative self-directed emotions, might be a promising approach in facilitating psychological adjustment also in LVAD patients. The aims of the present study were to investigate self-compassion as a protective factor for anxiety and depressive symptoms, to test whether taking a decentred perspective mediates these effects, and to explore whether self-compassion predicts the clinically rated functional health status. METHOD AND RESULTS: A sample of N = 45 patients (36 male) with a mean age of 60.5 years (SD = 10.8) from the outpatient department for terminal heart failure at the University Medical Center in Kiel, Germany, participated in the study. Patients completed self-report measures for psychological adjustment (HADS), self-compassion (SCS), and decentring (EQ). Functional health status was determined by the NYHA classification. The more patients were self-compassionate, the less they reported anxiety (r = -0.28) and depressive symptoms (r = -0.34). Decentring mediated both effects. Moreover, self-compassion predicted the functional health status, even when controlling for anxiety (odds ratio [OR] = 0.09) and depressive symptoms (OR = 0.11). CONCLUSIONS: This study provides the first evidence for a significant interrelation between self-compassion and common adverse psychological conditions in LVAD patients. Longitudinal data and the evaluation of interventions to strengthen self-compassion are needed to further validate the beneficial effects of self-compassion in LVAD patients in the future.
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Insuficiência Cardíaca , Coração Auxiliar , Ansiedade , Ajustamento Emocional , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/terapia , Coração Auxiliar/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , AutocompaixãoRESUMO
Levosimendan was first approved for clinic use in 2000, when authorisation was granted by Swedish regulatory authorities for the haemodynamic stabilisation of patients with acutely decompensated chronic heart failure. In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitisation and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced heart failure, right ventricular failure and pulmonary hypertension, cardiac surgery, critical care and emergency medicine. Levosimendan is currently in active clinical evaluation in the US. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and non-cardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, UK and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute heart failure arena in recent times and charts a possible development trajectory for the next 20 years.
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Levosimendan was first approved for clinical use in 2000, when authorization was granted by Swedish regulatory authorities for the hemodynamic stabilization of patients with acutely decompensated chronic heart failure (HF). In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitization and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced HF, right ventricular failure, pulmonary hypertension, cardiac surgery, critical care, and emergency medicine. Levosimendan is currently in active clinical evaluation in the United States. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and noncardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute HF arena in recent times and charts a possible development trajectory for the next 20 years.
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Cardiotônicos/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Contração Miocárdica/efeitos dos fármacos , Simendana/uso terapêutico , Vasodilatação/efeitos dos fármacos , Vasodilatadores/uso terapêutico , Cardiotônicos/efeitos adversos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Humanos , Segurança do Paciente , Simendana/efeitos adversos , Resultado do Tratamento , Vasodilatadores/efeitos adversosRESUMO
Acute and advanced heart failure are associated with substantial adverse short- and longer-term prognosis. Both conditions necessitate complex treatment choices to restore haemodynamic stability and organ perfusion, relieve congestion, improve symptoms and allow the patient to leave the hospital and achieve an adequate quality of life. Among the available intravenous vasoactive therapies, inotropes constitute an option when an increase in cardiac contractility is needed to reverse a low output state. Within the inotrope category, levosimendan is well suited to the needs of both sets of patients since, in contrast to conventional adrenergic inotropes, it has not been linked in clinical trials or wider clinical usage with increased mortality risk and retains its efficacy in the presence of beta-adrenergic receptor blockade; it is further believed to possess beneficial renal effects. The overall haemodynamic profile and clinical tolerability of levosimendan, combined with its extended duration of action, have encouraged its intermittent use in patients with advanced heart failure. This paper summarises the key messages derived from a series of 12 tutorials held at the Heart Failure 2019 congress organised in Athens, Greece, by the Heart Failure Association of the European Society of Cardiology.
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BACKGROUND: In 1997, a modified right atrial anastomosis (cavoatrial technique) for orthotopic heart transplantation (oHTx) was first developed in our institution. The purpose of this study is to report our long-term experience with this technique compared with biatrial and bicaval technique. METHODS: Retrospectively, 202 consecutive oHTx between 1997 and 2013 were analyzed. The applied transplantation techniques were biatrial (n = 108), bicaval (n = 22), and cavoatrial (n = 72). RESULTS: Demographic data were similar in all groups. The cardiopulmonary bypass and cross-clamp time were significantly shorter in the biatrial group. Follow-up echocardiographic examination showed excellent results in all groups with no relevant differences. After 1 year, occurrence of severe tricuspid regurgitation (biatrial 1.9% vs bicaval 0.0% vs cavoatrial 1.4%) was low in all groups. Rate of permanent pacemaker implantations was also low (12.0% vs 5.0% vs 11.1%). There were no significant differences in survival between the groups. CONCLUSION: The cavoatrial technique can be a safe and simple alternative for heart transplantation. Easy handling and similar reduced postoperative complications encourage the use of this technique.
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Átrios do Coração/transplante , Insuficiência Cardíaca/cirurgia , Transplante de Coração/métodos , Veia Cava Inferior/cirurgia , Veia Cava Superior/cirurgia , Adulto , Idoso , Anastomose Cirúrgica , Ponte Cardiopulmonar , Feminino , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Transplante de Coração/efeitos adversos , Transplante de Coração/mortalidade , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
Inotropes may be an appropriate response for some patients with advanced heart failure who remain highly symptomatic despite optimization of evidence-based therapy. These patients need to be supported waiting for a heart transplant or ventricular assist device, or may be candidates for inotropy as an intervention in its own right to maintain a patient in the best achievable circumstances. Objectives in such a situation include relieving symptoms, improving quality of life and reducing unplanned hospitalizations and the costs associated with such admissions. Levosimendan, a calcium sensitizer and potassium channel opener with inotrope and vasodilator actions, has emerged as a potentially valuable addition to the armamentarium in this context, used in repeated or intermittent cycles of therapy. Detailed proposals and guidance are offered for the identification of candidate patients with good prospects of a beneficial response to levosimendan, and for the safe and effective implementation of a course of therapy.
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Patients in the latest stages of heart failure are severely compromised, with poor quality of life and frequent hospitalizations. Heart transplantation and left ventricular assist device implantation are viable options only for a minority, and intermittent or continuous infusions of positive inotropes may be needed as a bridge therapy or as a symptomatic approach. In these settings, levosimendan has potential advantages over conventional inotropes (catecholamines and phosphodiesterase inhibitors), such as sustained effects after initial infusion, synergy with beta-blockers, and no increase in oxygen consumption. Levosimendan has been suggested as a treatment that reduces re-hospitalization and improves quality of life. However, previous clinical studies of intermittent infusions of levosimendan were not powered to show statistical significance on key outcome parameters. A panel of 45 expert clinicians from 12 European countries met in Rome on November 24-25, 2016 to review the literature and envision an appropriately designed clinical trial addressing these needs. In the earlier FIGHT trial (daily subcutaneous injection of liraglutide in heart failure patients with reduced ejection fraction) a composite Global Rank Score was used as primary end-point where death, re-hospitalization, and change in N-terminal-prohormone-brain natriuretic peptide level were considered in a hierarchical order. In the present study, we tested the same end-point post hoc in the PERSIST and LEVOREP trials on oral and repeated i.v. levosimendan, respectively, and demonstrated superiority of levosimendan treatment vs placebo. The use of the same composite end-point in a properly powered study on repetitive levosimendan in advanced heart failure is strongly advocated.
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Cardiotônicos/administração & dosagem , Conferências de Consenso como Assunto , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/epidemiologia , Hidrazonas/administração & dosagem , Piridazinas/administração & dosagem , Administração Oral , Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/normas , Esquema de Medicação , Europa (Continente)/epidemiologia , Medicina Baseada em Evidências/normas , Medicina Baseada em Evidências/tendências , Insuficiência Cardíaca/diagnóstico , Humanos , Infusões Intravenosas , Cidade de Roma/epidemiologia , SimendanaRESUMO
Background Sparse data are available on the prevalence of right ventricular dysfunction and/or pulmonary arterial hypertension in patients scheduled for cardiac surgery in Germany as well as on the intensity and modalities used for diagnosis, perioperative monitoring, and treatment of these comorbidities. Methods A postal survey including questions on the prevalence of preoperative right ventricular dysfunction and/or pulmonary arterial hypertension in patients undergoing cardiac surgery in 2009 was sent to 81 German heart centers. Total 47 of 81 (58%) heart centers returned the questionnaires. The centers reported data on 51,095 patients, and 49.8% of the procedures were isolated coronary artery bypass grafting. Results Data on the prevalence of preoperative pulmonary hypertension and/or right ventricular dysfunction were not available in 54% and 64.6% of centers. In the remaining hospitals, 19.5% of patients presented right heart dysfunction and 10% pulmonary arterial hypertension. Preoperative echocardiography was performed in only 45.3% of the coronary artery bypass grafting cases. Preoperative pharmacologic treatment of pulmonary hypertension or right ventricular dysfunction with oral sildenafil, inhaled prostanoids, or nitric oxide was initiated in 71% and 95.7% of the centers, respectively. Intra- and postoperative treatment was most frequently accomplished with phosphodiesterase-III inhibitors. Conclusion The prevalence of preoperative right heart dysfunction and pulmonary arterial hypertension in cardiac surgical patients in Germany seems to be substantial. However, in more than 50% of the patients, no preoperative data on right ventricular function and pulmonary arterial pressure are available. This may lead to underestimation of perioperative risk and inappropriate management of this high-risk population.
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Procedimentos Cirúrgicos Cardíacos , Hipertensão Pulmonar/epidemiologia , Disfunção Ventricular Direita/epidemiologia , Anti-Hipertensivos/uso terapêutico , Pressão Arterial , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ecocardiografia , Alemanha/epidemiologia , Inquéritos Epidemiológicos , Humanos , Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/fisiopatologia , Prevalência , Artéria Pulmonar/fisiopatologia , Medição de Risco , Fatores de Risco , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/tratamento farmacológico , Disfunção Ventricular Direita/fisiopatologia , Função Ventricular DireitaRESUMO
Colonization or infection with various pathogens is frequently found in patients listed for lung transplantation. We describe a case of a 50-year-old woman with α-1-antitrypsin deficiency, which was listed for double-lung transplantation, with multidrug-resistant gram-negative Acinetobacter baumannii (MRGN4-Ab) skin colonization. Transplantation was successfully performed. Colistin (Polymyxine E) was administered intravenously and through inhalation in the first month. MRGN4-Ab was still detectable in skin swabs without evidence of infection. After good recovery and clinical inapparence, the patient was discharged 2 months after transplantation.
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AIM: To investigate whether the endothelin ETA receptor blocker provides similar benefit on cardiac remodeling and survival in a hypertensive rat model of chronic heart failure (CHF). METHODS: Male stroke-prone spontaneously hypertensive (SHR-SP) rats were subjected to permanent ligation of the left coronary artery and were treated for 6 weeks with the endothelin ETA receptor blocker LU 135252 (30 mg.kg(-1).d(-1)) starting 24 h after ligation or untreatment. Sham-operated rats served as normal controls. The mean arterial blood pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP), left ventricular contractility (LV dp/dt(max)), left ventricular inner diameter (LVD) and circumference (LVC), septal thickness, left ventricular interstitial collagen content (ICC) and heart weight (HW) were measured at the end of the treatment. RESULTS: Compared with the untreated group, LU 135252 tended to increase HW (1.43 +/-0.03 vs 1.38 +/-0.04 g; P> 0.05), increased LVD (7.65+/-0.24 mm vs 6.58+/-0.14 mm; P<0.05), markedly increased LVC (30.11+/-0.83 mm vs 24.82+/-0.85 mm; P< 0.01) and reduced left ventricular ICC (3.79%+/-0.09% vs 6.71%+/-0.11%; P< 0.01), slightly lowered MAP (132+/-6 mmHg vs 142+/-4 mmHg; P>0.05), reduced LVEDP (14 4 mmHg vs 27+/-4 mmHg; P<0.05) and improved LV dp/dtmax (4230+/-450 mmHg/s vs 1950+/-400 mmHg/s; P<0.05); survival was not prolonged significantly (13% vs 11%; P=NS). CONCLUSION: In this hypertensive rat model of CHF, chronic endothelin ETA receptor blockade with LU 135252 improves cardiac hemodynamics, however, it does not affect long-term survival and worsens cardiac remodeling. Thus, endothelin ETA receptor antagonists are unlikely to have an important role in the management of patients with CHF.
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Antagonistas do Receptor de Endotelina A , Insuficiência Cardíaca/fisiopatologia , Miocárdio/patologia , Fenilpropionatos/farmacologia , Pirimidinas/farmacologia , Remodelação Ventricular/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Insuficiência Cardíaca/patologia , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/patologia , Hipertensão/fisiopatologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos SHRRESUMO
BACKGROUND: Bacterial infection has been discussed as a potential etiologic factor in the pathophysiology of coronary heart disease (CHD). This study analyzes molecular phylogenies to systematically explore the presence, frequency, and diversity of bacteria in atherosclerotic lesions in patients with CHD. METHODS AND RESULTS: We investigated 16S rDNA signatures in atherosclerotic tissue obtained through catheter-based atherectomy of 38 patients with CHD, control material from postmortem patients (n=15), and heart-beating organ donors (n=11) using clone libraries, denaturating gradient gel analysis, and fluorescence in situ hybridization. Bacterial DNA was found in all CHD patients by conserved PCR but not in control material or in any of the normal/unaffected coronary arteries. Presence of bacteria in atherosclerotic lesions was confirmed by fluorescence in situ hybridization. A high overall bacterial diversity of >50 different species, among them Staphylococcus species, Proteus vulgaris, Klebsiella pneumoniae, and Streptococcus species, was demonstrated in >1500 clones from a combined library and confirmed by denaturating gradient gel analysis. Mean bacterial diversity in atheromas was high, with a score of 12.33+/-3.81 (range, 5 to 22). A specific PCR detected Chlamydia species in 51.5% of CHD patients. CONCLUSIONS: Detection of a broad variety of molecular signatures in all CHD specimens suggests that diverse bacterial colonization may be more important than a single pathogen. Our observation does not allow us to conclude that bacteria are the causative agent in the etiopathogenesis of CHD. However, bacterial agents could have secondarily colonized atheromatous lesions and could act as an additional factor accelerating disease progression.
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Bactérias/isolamento & purificação , Doença da Artéria Coronariana/microbiologia , Doença das Coronárias/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Aterectomia , Aterosclerose/etiologia , Aterosclerose/microbiologia , Bactérias/genética , Infecções Bacterianas/complicações , Doença da Artéria Coronariana/etiologia , Doença das Coronárias/etiologia , DNA Ribossômico/análise , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-IdadeRESUMO
AIM: To elucidate the cardioprotective effects of T-type calcium channel blocker mibefradil and compare with that of the angiotensin-converting enzyme inhibitor ramipril in a stroke-prone spontaneously hypertensive rats (SHR-SP) model of congestive heart failure (CHF) after myocardial infarction (MI). METHODS: SHR-SP rats were subjected to permanent ligation of the left anterior decending coronary artery. Treatment with mibefradil (10 mg.kg(-1).d(-1)), ramipril (10 mg.kg(-1).d(-1)), or placebo was initiated 4 weeks before surgery and continued up to 6 weeks after induction of MI. Sham-operated rats served as controls. RESULTS: In placebo-treated MI rats, six weeks after MI, left ventricular circumference, inner diameter, and left ventricular end-diastolic pressure (LVEDP) were increased, whereas mean arterial blood pressure (MAP) and maximum rate of rise of left ventricular pressure (dp/dt(max)) were decreased compared with sham-operated controls (P<0.01). In ramipril-treated MI rats, heart weight, heart weight to body weight ratio and interstitial collagen content were reduced (P<0.05, P<0.01), LVEDP was slightly decreased (P>0.05), and dp/dt(max) was improved (P<0.01) compared with placebo-treated MI rats. In contrast, in mibefradil-treated MI rats, heart weight, heart weight to body weight ratio were slightly but not significantly reduced, LVEDP was slightly elevated compared with placebo-treated MI rats, and was elevated (P<0.05) compared with ramipril-treated MI rats, although interstitial collagen content were reduced (P<0.01) compared with placebo-treated MI rats. CONCLUSION: Chronic treatment with ramipril diminishes cardiac remodeling of heart failure after MI to a greater extent than mibefradil. Moreover, 6 weeks after MI, mibefradil treatment results in a slight rise in LVEDP compared with placebo-treated rats. Therefore, treatment with mibefradil might be deleterious rather than beneficial compared with ramipril or even placebo treatment in experimental MI.
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Cardiotônicos/farmacologia , Mibefradil/farmacologia , Infarto do Miocárdio/fisiopatologia , Ramipril/farmacologia , Remodelação Ventricular/efeitos dos fármacos , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/farmacologia , Coração/anatomia & histologia , Frequência Cardíaca/efeitos dos fármacos , Infarto do Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos SHR , Pressão Ventricular/efeitos dos fármacosRESUMO
The AT2 receptor regulates several functions of nerve cells, e.g., ionic fluxes, cell differentiation, and axonal regeneration, but also modulates programmed cell death. We tested the hypothesis that angiotensin II (ANG II) via its AT2 receptor not only promotes regeneration but also functional recovery after sciatic nerve crush in adult rats. ANG II (10(-7), 10(-9), 10(-11) M) applied locally via osmotic minipumps promoted functional recovery with maximal effects after the lowest concentration. The toe spread distance as a parameter for re-innervation after 20 days was significantly (P<0.01) greater (10.2+/-10.27 mm) compared with the control group (8.73+/-0.16 mm). The response to local electrical stimulation (return of sensorimotor function) was reduced to 14.6 days vs. 17.9 days in the control group (P<0.01). The AT2 receptor antagonist PD 123319 administered alone or in combination with ANG II completely prevented the ANG II-induced recovery, whereas the AT1 receptor antagonist losartan had no effect. Furthermore, ANG II induces, via the AT2 receptor, activation of the transcription factor NF-kappaB in Schwann cells. Histological criteria, morphometric analyses, and electron microscopy confirmed the functional data. These results are the first to present direct evidence for an involvement of the AT2 receptor and NF-kappaB in peripheral nerve regeneration.
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Angiotensina II/farmacologia , NF-kappa B/fisiologia , Regeneração Nervosa/efeitos dos fármacos , Receptor Tipo 2 de Angiotensina/fisiologia , Nervo Isquiático/fisiologia , Animais , Axônios/fisiologia , Axônios/ultraestrutura , Pé/inervação , Cinética , Bainha de Mielina/fisiologia , Compressão Nervosa , Ratos , Células de Schwann/metabolismo , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/cirurgiaRESUMO
The present study examined non-insulin-treated streptozotocin (STZ)-induced diabetic rats to determine the role of kinins in diabetic nephropathy. Their involvement in the renoprotective effect of the angiotensin-converting enzyme inhibitor (ACEI) ramipril was investigated using the bradykinin (BK) B(2)-receptor antagonist, icatibant (HOE 140), or a combination of the two drugs.Although, none of the treatments prevented the decline of the glomerular filtration rate (GFR) in diabetic rats, ramipril (3 mg/kg/day), but not icatibant (HOE 140; 500 microg/kg/day), prevented proteinuria in these animals. However, the antiproteinuric effect of ramipril was reduced by 45% when combined with icatibant. To explore whether the renal kallikrein-kinin system (KKS) belongs to the underlying mechanisms of these findings, we also determined urinary BK levels, renal kallikrein (KLK) and angiotensin-converting enzyme (ACE) activity as well as renal cortical mRNA levels of neutral endopeptidase 24.11 (NEP) and low-molecular weight (LMW) kininogen. STZ led to a reduction of renal KLK and ACE activity and NEP expression and to a three-fold increase of urinary BK excretion and renal kininogen expression. Icatibant given alone had no effect on these parameters. In contrast, ramipril treatment normalized urinary protein and BK excretion as well as kininogen mRNA expression without affecting NEP mRNA expression or KLK and ACE activity. Our data demonstrate that renal BK is increased in severe STZ-induced diabetes mellitus, but may affect glomerular regulation only to a minor degree under this condition. However, kinins are partly involved in the antiproteinuric action of ACEI at this stage of diabetic nephropathy.