Ecto-5'-nucleotidase mediates infarct size-limiting effect by ischemic preconditioning in the rabbit heart.
We examined whether ecto-5'-nucleotidase mediates infarct limitation by ischemic preconditioning in the rabbit heart. Ecto-5'-nucleotidase activity in ischemic region after ischemic preconditioning was greater than that in nonischemic regions (23.6 +/- 2.5 vs. 13.6 +/- 1.0 nmol/mg protein/min; p < 0.01). With an inhibitor of 5'-nucleotidase, alpha,beta-methylene adenosine 5'-diphosphate (AMP-CP), ecto-5'-nucleotidase activity in the ischemic region was comparable to that in the nonischemic region. Mean blood pressure was reduced from 73 +/- 2 to 62 +/- 3 mm Hg with intravenous AMP, whereas it did not change with coperfusion of AMP and AMP-CP, suggesting effective inhibition of ecto-5'-nucleotidase. Separately, myocardial infarction was created by 30-min coronary occlusion and 3 h of reperfusion. Infarct size expressed as percentage volume in risk area was reduced by ischemic preconditioning compared with that in the control (7.8 +/- 2.5% vs. 38.1 +/- 4.0%; p < 0.01). However, infarct size in the group given AMP-CP plus ischemic preconditioning was similar to that in the control (36.2 +/- 2.8% vs. 38.1 +/- 4.0%; NS), suggesting that ecto-5'-nucleotidase mediates infarct limitation by ischemic preconditioning in the rabbit.
Komamura
K
K
The First Department of Medicine, Osaka University School of Medicine, Japan.
Kitakaze
M
M
Funaya
H
H
Ueda
Y
Y
Node
K
K
Minamino
T
T
Kurihara
T
T
Hori
M
M
D015720:5'-Nucleotidase / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D009203:Myocardial Infarction / Q000201:enzymology*; D011817:Rabbits
D004791:Enzyme Inhibitors; C523965:alpha,beta-methyleneadenosine 5'-diphosphate; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D015720:5'-Nucleotidase