Cardioprotection conferred by exercise training is blunted by blockade of the opioid system
Clinics
; 66(1): 151-157, 2011. ilus, tab
Artigo
em Inglês
| LILACS
| ID: lil-578612
Biblioteca responsável:
BR1.1
ABSTRACT
OBJECTIVES:
To investigate the effect of opioid receptor blockade on the myocardial protection conferred by chronic exercise and to compare exercise training with different strategies of myocardial protection (opioid infusion and brief periods of ischemia-reperfusion) preceding irreversible left anterior descending coronary ligation.INTRODUCTION:
The acute cardioprotective effects of exercise training are at least partly mediated through opioid receptor-dependent mechanisms in ischemia-reperfusion models.METHODS:
Male Wistar rats (n = 76) were randomly assigned to 7 groups (1) control; (2) exercise training; (3) morphine; (4) intermittent ischemia-reperfusion (three alternating periods of left anterior descending coronary occlusion and reperfusion); (5) exercise training+morphine; (6) naloxone (a non-selective opioid receptor blocker) plus morphine; (7) naloxone before each exercise-training session. Myocardial infarction was established in all groups by left anterior descending coronary ligation. Exercise training was performed on a treadmill for 60 minutes, 5 times/week, for 12 weeks, at 60 percent peak oxygen (peak VO2). Infarct size was histologically evaluated.RESULTS:
Exercise training significantly increased exercise capacity and ΔVO2 (VO2 peak - VO2 rest) (p<0.01 vs. sedentary groups). Compared with control, all treatment groups except morphine plus naloxone and exercise training plus naloxone showed a smaller infarcted area (p<0.05). No additional decrease in infarct size occurred in the exercise training plus morphine group. No difference in myocardial capillary density (p = 0.88) was observed in any group.CONCLUSIONS:
Exercise training, morphine, exercise training plus morphine and ischemia-reperfusion groups had a smaller infarcted area than the control group. The effect of chronic exercise training in decreasing infarct size seems to occur, at least in part, through the opioid receptor stimulus and not by increasing ...
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Contexto em Saúde:
Agenda de Saúde Sustentável para as Américas
Problema de saúde:
Objetivo 9: Redução de doenças não transmissíveis
Base de dados:
LILACS
Assunto principal:
Condicionamento Físico Animal
/
Receptores Opioides
/
Infarto do Miocárdio
Tipo de estudo:
Estudo observacional
/
Estudo prognóstico
Limite:
Animais
Idioma:
Inglês
Revista:
Clinics
Assunto da revista:
Medicina
Ano de publicação:
2011
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Universidade de São Paulo/BR