FERNANDO LUIZ ZANONI
Projetos de Pesquisa
Unidades Organizacionais
LIM/11 - Laboratório de Cirurgia Cardiovascular e Fisiopatologia da Circulação, Hospital das Clínicas, Faculdade de Medicina
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
- Bilateral sympathectomy improves postinfarction left ventricular remodeling and function(2017) ZANONI, Fernando Luiz; SIMAS, Rafael; SILVA, Raphael Grillo da; BREITHAUPT-FALOPPA, Ana Cristina; SILVA, Raphael dos Santos Coutinho e; JATENE, Fabio Biscegli; MOREIRA, Luiz Felipe P.Objectives: To evaluate the influence of bilateral or left sympathectomy on left ventricular remodeling and function after myocardial infarction in rats. Methods: Myocardial infarction was induced in rats by ligation of the left anterior descending coronary. Seven days later, rats were divided into 4 groups: the myocardial infarction, myocardial infarction with left sympathectomy, myocardial infarction with bilateral sympathectomy, and sham groups. After 8 weeks, left ventricular function was evaluated with the use of a pressure-volume conductance catheter under steady-state conditions and pharmacological stress. Infarct size and extracellular matrix fibrosis were evaluated, and cardiac matrix metalloproteinases and myocardial inflammatory markers were analyzed. Results: The myocardial infarction and left sympathectomy group had an increased end diastolic volume, whereas the bilateral sympathectomy group had a mean end-diastolic volume similar to that of the sham group (P <. 002). Significant reduction in ejection fraction was observed in the myocardial infarction and left sympathectomy group, whereas it was preserved after bilateral sympathectomy (P < .001). In response to dobutamine, left ventricular contractility increased in sham rats, rising stroke work, cardiac output, systolic volume, end-diastolic volume, ejection fraction, and dP/dt max. Only bilateral sympathectomy rats had significant increases in ejection fraction (P <. 001) with dobutamine. Fibrotic tissue and matrix metalloproteinase expression decreased in the bilateral sympathectomy group compared to that in the myocardial infarction group (P <. 001) and was associated with left ventricular wall thickness maintenance and better apoptotic markers in noninfarcted myocardium. Conclusions: Bilateral sympathectomy effectively attenuated left ventricular remodeling and preserved systolic function after myocardial infarction induction in rats.
- Cardiac MicroRNA Expression Profile After Experimental Brain Death Is Associated With Myocardial Dysfunction and Can Be Modulated by Hypertonic Saline(2022) FERREIRA, Ludmila Rodrigues Pinto; CORREIA, Cristiano Jesus; ZANONI, Fernando Luiz; CARVALHO-SILVA, Ana Carolina; ZANIRATTO, Ricardo; CANDIDO, Darlan da Silva; ALMEIDA, Rafael Ribeiro; BREITHAUPT-FALOPPA, Ana Cristina; CUNHA-NETO, Edecio; MOREIRA, Luiz Felipe P.Background. Brain death (BD) is associated with systemic inflammatory compromise, which might affect the quality of the transplanted organs. This study investigated the expression profile of cardiac microRNAs (miRNAs) after BD, and their relationship with the observed decline in myocardial function and with the changes induced by hypertonic saline solution (HSS) treatment. Methods. Wistar rats were assigned to sham-operation (SHAM) or submitted to BD with and without the administration of HSS. Cardiac function was assessed for 6 h with left ventricular (LV) pressure-volume analysis. We screened 641 rodent miRNAs to identify differentially expressed miRNAs in the heart, and computational and functional analyses were performed to compare the differentially expressed miRNAs and find their putative targets and their related enriched canonical pathways. Results. An enhanced expression in canonical pathways related to inflammation and myocardial apoptosis was observed in BD induced group, with 2 miRNAs, miR-30a-3p, and miR-467f, correlating with the level of LV dysfunction observed after BD. Conversely, HSS treated after BD and SHAM groups showed similar enriched pathways related to the maintenance of heart homeostasis regulation, in agreement with the observation that both groups did not have significant changes in LV function. Conclusions. These findings highlight the potential of miRNAs as biomarkers for assessing damage in BD donor hearts and to monitor the changes induced by therapeutic measures like HSS, opening a perspective to improve graft quality and to better understand the pathophysiology of BD. The possible relation of BD-induced miRNA's on early and late cardiac allograft function must be investigated.
- Thoracic bilateral sympathectomy attenuates oxidative stress and prevents ventricular remodelling in experimental pulmonary hypertension(2022) SILVA, Raphael dos Santos Coutinho e; WIGGENHAUSER, Lucas Moritz; SIMAS, Rafael; ZANONI, Fernando Luiz; MEDEIROS, Geisla; SILVA, Fernanda Beatriz da; OGATA, Daniel Cury; BREITHAUPT-FALOPPA, Ana Cristina; KRENNING, Guido; MOREIRA, Luiz Felipe PinhoOBJECTIVES: Pulmonary arterial hypertension (PAH) is a cardiopulmonary disease that affects the pulmonary vasculature, leading to increased afterload and eventually right ventricular (RV) remodelling and failure. Bilateral sympathectomy (BS) has shown promising results in dampening cardiac remodelling and dysfunction in several heart failure models. In the present study, we investigated whether BS reduces pulmonary arterial remodelling and mitigates RV remodelling and failure. METHODS: PAH was induced in male Wistar rats by intraperitoneal injection of monocrotaline. Rats were divided into 3 groups, involving untreated PAH (n = 15), BS-treated PAH (n = 13) and non-manipulated control rats (n = 13). Three weeks after PAH induction, the rats were anaesthetized and RV function was assessed via the pressure-volume loop catheter approach. Upon completion of the experiment, the lungs and heart were harvested for further analyses. RESULTS: BS was found to prevent pulmonary artery remodelling, with a clear reduction in alpha-smooth muscle actin and endothelin-1 expression. RV end-systolic pressure was reduced in the BS group, and preload recruitable stroke work was preserved. BS, therefore, mitigated RV remodelling and cardiomyocyte hypertrophy and diminished oxidative stress. CONCLUSIONS: We showed that thoracic BS may be an important treatment option for PAH patients. Blockade of the sympathetic pathway can prevent pulmonary remodelling and protect the RV from oxidative stress, myocardial remodelling and function decay. Pulmonary arterial hypertension (PAH) is a cardiopulmonary disease that affects both the pulmonary vasculature and the right ventricle (RV).
conferenceObject EFFECTS OF HYPERTONIC SALINE SOLUTION ON CARDIAC AND PULMONARY CHANGES AFTER BRAIN DEATH: AN EXPERIMENTAL STUDY(2017) CORREIA, Cristiano; MAGGALHAES, Daniel M.; ZANONI, Fernando; SIMAS, Rafael; SOARES, Rafaela Garcia Ferreira; SILVA, Raphael S. Coutinho E; BREITHAUPT-FALOPPA, Ana Cristina; SANNOMIYA, Paulina; MOREIRA, Luiz FelipeconferenceObject Remote Ischemic Preconditioning Does Not Prevent Placental Dysfunction Induced by Extrcorporeal Circulation in Fetal Lambs(2019) ASSAD, Renato S.; GUEDES, Marcelo G.; AIELLO, Vera D.; THOMAZ, Petronio G.; ZANONI, Fernando L.; ARASHIRO, Ana Cristina A.; SILVA, Ana Paula N. da; SILVA, Raphael S. Coutinho e; FALOPPA, Ana Cristina B.; PINTO, Marcelo V.; JATENE, Marcelo B.; MOREIRA, Luiz Felipe P.- Effect of bilateral sympathectomy in a rat model of dilated cardiomyopathy induced by doxorubicin(2020) SILVA, Raphael dos Santos Coutinho e; ZANONI, Fernando Luiz; SIMAS, Rafael; SILVA, Mateus Henrique Fernandes Martins da; ARMSTRONG JUNIOR, Roberto; CORREIA, Cristiano de Jesus; FALOPPA, Ana Cristina Breithaupt; MOREIRA, Luiz Felipe PinhoObjective: The study objective was to evaluate the effect of bilateral sympathectomy on ventricular remodeling and function in a rat model of dilated cardiomyopathy induced by doxorubicin. Methods: Dilated cardiomyopathy was induced in male Wistar rats by weekly intraperitoneal injection of doxorubicin (2 mg/kg) for 9 weeks. Animals were divided into 4 groups: dilated cardiomyopathy; bilateral sympathectomy, submitted on day 15 of the protocol to bilateral sympathectomy; angiotensin-converting enzyme inhibitor, treated with enalapril through day 15 until the end of the experimental protocol; and sham, nonsubmitted through doxorubicin protocol, with weekly intraperitoneal injections of saline solution (0.9%). The left ventricular function was assessed, and the heart was collected for posterior analyses. Results: The dilated cardiomyopathy group presented a significant decrease in the myocardial efficiency when compared with the sham group (33.4% vs 71.2%). Only the bilateral sympathectomy group was able to preserve it (57.5%; P = .0001). A significant dilatation in the left ventricular chamber was observed in the dilated cardiomyopathy group (15.9 mu m(2)) compared with the sham group (10.2 mu m(2); P = .0053). Sympathectomy and enalapril prevented ventricular remodeling (9.5 and 9.6 mu m(2), respectively; P = .0034). There was a significant increase in interstitial myocardial fibrosis in the dilated cardiomyopathy group (14.8%) when compared with the sham group (2.4%; P = .0001). This process was significantly reduced with sympathectomy and enalapril (8.7 and 3.9%, respectively; P = .0001). Conclusions: Bilateral sympathectomy was effective in preventing remodeling and left ventricular dysfunction in a rat model of dilated cardiomyopathy induced by doxorubicin.