Short-term diabetes attenuates left ventricular dysfunction and mortality rates after myocardial infarction in rodents

Autor(es)

Rodrigues, Bruno ^{[1, 2]} ; Taboas Figueroa, Diego Mendrot ^[1] ; Fang, Jiao ^[1] ; Rosa, Kaleizu Teodoro ^[1] ; Llesuy, Suzana ^[3] ; De Angelis, Katia ^[4] ; Irigoyen, Maria Claudia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med, Heart Inst InCor, Hypertens Unit, Sao Paulo - Brazil

^[2] Univ Sao Judas Tadeu, Human Movement Lab, Sao Paulo - Brazil

^[3] Univ Buenos Aires, Fac Farm & Bioquim, Catedra Quim Gen & Inorgan, RA-1113 Buenos Aires, DF - Argentina

^[4] Nove de Julho Univ, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Clinics; v. 66, n. 8, p. 1437-1442, 2011.
• Citações Web of Science: 9

Resumo

OBJECTIVES: To investigate the effects of hyperglycemia on left ventricular dysfunction, morphometry, myocardial infarction area, hemodynamic parameters, oxidative stress profile, and mortality rate in rats that had undergone seven days of myocardial infarction. INTRODUCTION: Previous research has demonstrated that hyperglycemia may protect the heart against ischemic injury. METHODS: Male Wistar rats were divided into four groups: control-sham, diabetes-sham, myocardial infarction, and diabetes + myocardial infarction. Myocardial infarction was induced 14 days after diabetes induction. Ventricular function and morphometry, as well as oxidative stress and hemodynamic parameters, were evaluated after seven days of myocardial infarction. RESULTS: The myocardial infarction area, which was similar in the infarcted groups at the initial evaluation, was reduced in the diabetes + myocardial infarction animals (23 ± 3%) when compared with the myocardial infarction (42 ± 7%, p<0.001) animals at the final evaluation. The ejection fraction (22%, p = 0.003), velocity of circumferential fiber shortening (30%, p = 0.001), and left ventricular isovolumetric relaxation time (26%, p = 0.002) were increased in the diabetes + myocardial infarction group compared with the myocardial infarction group. The diabetes-sham and diabetes + myocardial infarction groups displayed increased catalase concentrations compared to the control-sham and myocardial infarction groups (diabetes-sham: 32± 3; diabetes + myocardial infarction: 35± 0.7; control-sham: 12 ± 2; myocardial infarction: 16 ± 0.1 pmol min-1 mg-1 protein). The levels of thiobarbituric acid-reactive substances were reduced in the diabetes-sham rats compared to the control-sham rats. These positive adaptations were reflected in a reduced mortality rate in the diabetes + myocardial infarction animals (18.5%) compared with the myocardial infarction animals (40.7%, p = 0.001). CONCLUSIONS: These data suggest that short-term hyperglycemia initiates compensatory mechanisms, as demonstrated by increased catalase levels, which culminate in improvements in the ventricular response, infarcted area, and mortality rate in diabetic rats exposed to ischemic injury. (AU)

• Processo FAPESP: 07/57595-5 - Efeitos do treinamento físico no controle autônomo cardiovascular em fêmeas saudáveis e submetidas à privação dos hormônios ovarianos: papel do estresse oxidativo
• Beneficiário: Kátia de Angelis Lobo D Avila
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 01/00009-0 - Estudo integrado da hipertensão arterial: caracterização molecular e funcional do sistema cardiovascular
• Beneficiário: Eduardo Moacyr Krieger
• Modalidade de apoio: Auxílio à Pesquisa - Temático