Diabetic hyperglycemia attenuates sympathetic dysfunction and oxidative stress after myocardial infarction in rats

Cardiovascular Diabetology

Original Investigation

Catarina Andrade Barboza¹  Bruno Rodrigues¹  Maria-Cláudia Irigoyen²  Renata Kelly da Palma³  Camila Paixão dos Santos³  Kátia De Angelis³  Sarah Cristina Ferreira Freitas³  Christiane Malfitano³  Susana Llesuy⁴  Adriane Belló-Klein⁵  Cristiano Mostarda⁶ 

[1] Human Movement Laboratory, Universidade São Judas Tadeu UST, São Paulo, SP, Brazil;Hypertension Unit, Heart Institute (InCor), Medical School of University of São Paulo, São Paulo, SP, Brazil;Translation Physiology Laboratory, Universidade Nove de Julho (UNINOVE, Vergueiro 235/249 - 2° subsolo - Mestrado, Zip Code 01504 001, São Paulo, SP, Brazil;Translation Physiology Laboratory, Universidade Nove de Julho (UNINOVE, Vergueiro 235/249 - 2° subsolo - Mestrado, Zip Code 01504 001, São Paulo, SP, Brazil;Cátedra de Química General y Inorgánica, Facultad de Farmácia y Bioquimica, Universidad de Buenos Aires, Buenos Aires, Argentina;Translation Physiology Laboratory, Universidade Nove de Julho (UNINOVE, Vergueiro 235/249 - 2° subsolo - Mestrado, Zip Code 01504 001, São Paulo, SP, Brazil;Laboratório de Fisiologia Cardiovascular e Espécies Ativas de Oxigênio, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil;Universidade Federal do Maranhão (UFMA), São Luís, MA, Brazil;Hypertension Unit, Heart Institute (InCor), Medical School of University of São Paulo, São Paulo, SP, Brazil;

关键词: Autonomic modulation;    Oxidative stress;    Diabetic hyperglycemia;    Myocardial infarction;   

DOI  :  10.1186/s12933-014-0131-x

 received in 2014-06-10, accepted in 2014-08-29,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundPrevious research has demonstrated that hyperglycemia may protect the heart against ischemic injury. The aim of the present study was to investigate the association between hyperglycemia and myocardial infarction on cardiovascular autonomic modulation and cardiac oxidative stress profile in rats. Male Wistar rats were divided into: control (C), diabetic (D), myocardial infarcted (MI) and diabetic infarcted rats (DMI).MethodsDiabetes was induced by streptozotocin (STZ, 50 mg/Kg) at the beginning of the protocol and MI was induced by left coronary occlusion 15 days after STZ. Thirty days after streptozocin-induced diabetes, cardiovascular autonomic modulation was evaluated by spectral analysis, and oxidative stress profile was determined by antioxidant enzyme activities and superoxide anion, together with protein carbonylation and redox balance of glutathione (GSH/GSSG).ResultsThe diabetic and infarcted groups showed decreased heart rate variability and vagal modulation (p < 0.05); however, sympathetic modulation decreased only in diabetic groups (p < 0.05). Sympatho/vagal balance and vascular sympathetic modulation were increased only in the MI group (p < 0.05). Diabetes promoted an increase in catalase concentration (p < 0.05). Glutathione peroxidase activity was increased only in DMI when compared to the other groups (p < 0.05). Superoxide anion and protein carbonylation were increased only in MI group (p < 0.05). Cardiac redox balance, as evaluated by GSH/GSSG, was lower in the MI group (p < 0.05).ConclusionsThese data suggest that hyperglycemia promotes compensatory mechanisms that may offer protection against ischemia, as demonstrated by increased antioxidants, decreased pro-oxidants and protein damage, possibly related to the improvements in both redox balance and sympathetic modulation to the heart.

【 授权许可】

CC BY   
© Malfitano et al.; licensee BioMed Central Ltd. 2014