MARCIA KIYOMI KOIKE
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Clínica Médica, Faculdade de Medicina
LIM/51 - Laboratório de Emergências Clínicas, Hospital das Clínicas, Faculdade de Medicina
LIM/51 - Laboratório de Emergências Clínicas, Hospital das Clínicas, Faculdade de Medicina
2 resultados
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- Cardiac benefits of exercise training in aging spontaneously hypertensive rats(2011) ROSSONI, Luciana V.; OLIVEIRA, Raphael A. F.; CAFFARO, Rene R.; MIANA, Maria; SANZ-ROSA, David; KOIKE, Marcia K.; AMARAL, Sandra L. Do; MICHELINI, Lisete C.; LAHERA, Vicente; CACHOFEIRO, VictoriaObjective To evaluate the effect of low-intensity chronic exercise training (ExT) on blood pressure (BP), as well as the cardiac alterations associated with hypertension in aging hypertensive rats. Methods Male spontaneously hypertensive rats (SHR; 21 months old) and their normotensive control Wistar-Kyoto (WKY) rats were submitted to low-intensity training protocol for 13 weeks. BP, cardiac morphological and morphometric analysis, as well as gene expression of fibrotic and inflammatory factors were analyzed at the end of the training period. Results ExT reduced BP and heart rate in aged SHR. Left ventricle hypertrophy, collagen volume fraction and wall-to-lumen ratio of myocardium arterioles were also decreased in trained SHR. However, ExT was unable to reverse the either reduced capillary density or the cardiac myocyte hypertrophy observed in SHR as compared with WKY rats. Trained SHR showed higher metalloproteinase-2/tissue inhibitor metalloproteinase-2 (MMP-2/TIMP-2) ratio and lower levels of a-smooth muscle actin, but similar levels of connective tissue growth factor, transforming growth factor beta or IL-1 beta to that of nontrained SHR. Conclusion Low to moderate-intensity chronic ExT reverses the cardiac alterations associated with hypertension: myocardial arteriole, left ventricle hypertrophy, collagen content and tachycardia. These changes could be consequence or cause of the reduction in BP observed in trained SHR. In addition, ExT does not worsen the underlying inflammatory burden associated with hypertension. Therefore, the data support a beneficial effect of ExT in aging SHR similar to that reported in young or middle-aged individuals, confirming that exercise is a healthy habit that induces cardiac improvements independently of age. J Hypertens 29: 2349-2358 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
- Early activation of ubiquitin-proteasome system at the diaphragm tissue occurs independently of left ventricular dysfunction in SHR rats(2020) SOUZA, Pamella Ramona Moraes de; PALMA, Renata Kelly da; VIEIRA, Rodolfo Paula; SANTOS, Fernando dos; MONTEIRO-DE-MORAES, Wilson Max Almeida; MEDEIROS, Alessandra; KOIKE, Marcia Kiyomi; ARANTES-COSTA, Fernanda Magalhaes; ANGELIS, Katia De; IRIGOYEN, Maria Claudia; COLOMBO, Fernanda Marciano ConsolimHypertensive status induces modifications in the respiratory profile. Previous studies have indicated that hypertensive rats show increased respiratory-sympathetic coupling compared to normotensive rats. However, these effects and especially the mechanisms underlying such effects are not well known. Thus, we evaluated the influence of high blood pressure and autonomic dysfunction on a ventilatory pattern associated with lung injury and on the ubiquitin-proteasome system of the diaphragm muscle. Autonomic cardiovascular modulation (systolic BP variance and low-frequency band and pulse interval variance) and arterial blood gases patterns (pH, pO(2), HCO3, SpO(2)), can be changed by hypertension, as well exacerbated chemoreflex pressor response. We observed that the diaphragm muscle of SHR showed increase in type I cross-sectional fiber (16%) and reduction in type II cross-sectional fiber area (41%), increased activity of the ubiquitin-proteasome system and lipid peroxidation, with no differences between groups in the analysis of ubiquitinated proteins and misfolded proteins. Our results showed that hypertension induced functional compensatory/adverse alterations associated with diaphragm fiber type changes and protein degradation as well as changed autonomic control of circulation. In conclusion, we believe there is an adaptation in ventilatory pattern in regarding to prevent the development of fatigue and muscle weakness and improve ventilatory endurance. Impact statement It was well known that hypertension can be driven by increased sympathetic activity and has been documented as a central link between autonomic dysfunction and alterations in the respiratory pattern. Our study demonstrated the impact of hypertension in ventilatory mechanics and their relationship with diaphragm muscle protein degradation. These findings may assist us in future alternative treatments to prevent diaphragm fatigue and weakness in hypertensive patients.