Effect of Exercise Intensity on Adenosine Metabolism in Systemic Circulation and Cardiovascular Protection

Abstract

Adenosine is believed to be one of the main mediators of the cardioprotective effects of ischemic preconditioning and exercise preconditioning in the body. Sprague Dawley rats (SDR) were each exercised on a treadmill for 15 minutes at 10 m/min and 10% grade (n = 13) (LowEx), or 14 m/min and 22% grade (n = 14) (VigEx). Two hours after the exercise, rats from the LowEx group (n = 7) and those from the VigEx group (n = 8) were each received a single dose of isoproterenol (ISO) (30 mg/kg) by subcutaneous (sc) injection. The remainders were injected with normal saline. The mortality rate of the rats exposed to ISO was 25% in VigEx group and 57% in the LowEx group. Exercise intensity affected the levels of ADO in such a way that it was significantly higher in the LowEx group in both ISO and NS treated group.