Exercise training prevents the attenuation of anesthetic pre-conditioning-mediated cardioprotection in diet-induced obese rats.

Acta anaesthesiologica Scandinavica

PubMedID: 25312305

Li L, Meng F, Li N, Zhang L, Wang J, Wang H, Li D, Zhang X, Dong P, Chen Y. Exercise training prevents the attenuation of anesthetic pre-conditioning-mediated cardioprotection in diet-induced obese rats. Acta Anaesthesiol Scand. 2014;.
BACKGROUND
Obesity abolishes anesthetic pre-conditioning-induced cardioprotection due to impaired reactive oxygen species (ROS)-mediated adenosine monophosphate-activated protein kinase (AMPK) pathway, a consequence of increased basal myocardial oxidative stress. Exercise training has been shown to attenuate obesity-related oxidative stress.

OBJECTIVE
This study tests whether exercise training could normalize ROS-mediated AMPK pathway and prevent the attenuation of anesthetic pre-conditioning-induced cardioprotection in obesity.

METHODS
Male Sprague-Dawley rats were divided into lean rats fed with control diet and obese rats fed with high-fat diet. After 4 weeks of feeding, lean and obese rats were assigned to sedentary conditions or treadmill exercise for 8 weeks.

RESULTS
There was no difference in infarct size between lean sedentary and obese sedentary rats after 25?min of myocardial ischemia followed by 120?min reperfusion. In lean rats, sevoflurane equally reduced infarct size in lean sedentary and lean exercise-trained rats. Molecular studies revealed that AMPK activity, endothelial nitric oxide synthase, and superoxide production measured at the end of ischemia in lean rats were increased in response to sevoflurane. In obese rats, sevoflurane increased the above molecular parameters and reduced infarct size in obese exercise-trained rats but not in obese sedentary rats. Additional study showed that obese exercise-trained rats had decreased basal oxidative stress than obese sedentary rats.

CONCLUSION
The results indicate that exercise training can prevent the attenuation of anesthetic cardioprotection in obesity. Preventing the attenuation of this strategy may be associated with reduced basal oxidative stress and normalized ROS-mediated AMPK pathway, but the causal relationship remains to be determined.