Korean J Physiol Pharmacol.
1999 Feb;3(1):53-57.
Role of Adenosine in the Activation of Myocardial Catalase Induced by Brief Regional Ischemia
- Affiliations
-
- 1Department of Pharmacology, Seoul National University College of Medicine, 28 Yongon-dong, Chong South Korea.
- 2Department of Pharmacology & Heart Research Institute, Seoul National University College of Medicine, Seoul 110-799, Korea .
Abstract
-
The activities of myocardial antioxidant enzymes are known to increase
in the hearts preconditioned with the brief episodes of ischemia. This
study was undertaken to elucidate the possible involvement of adenosine
in the stimulation of myocardial catalase induced by the brief regional
ischemia in rabbit hearts. Coronary artery descending the middle
anterior wall of left ventricle was occluded for 15 min, followed by 1
hr of reperfusion. Upon reperfusion after the brief ischemia, the
activity of catalase increased significantly in both ischemic and
non-ischemic parts of myocardium. Pretreatment of the heart with
theophylline, a non-specific adenosine receptor blocker, completely
abolished the increase of catalase activity in both the ischemic and
non-ischemic regions of myocardium. On the other hand, the
administration of exogenous adenosine instead of the ischemia failed to
increase the catalase activity in in vivo hearts. Moreover, adenosine
infusion did not affect the catalase activity in the isolated, perfused
hearts either. These results suggest that the endogenous adenosine
released from the ischemic myocardium is involved in the activation of
catalase induced by brief ischemia, but that adenosine may not be a
final direct activator of cellular catalase in the myocardium.