Effects of L-arginine administration before cardioplegic arrest on ischemia-reperfusion injury.
BACKGROUND
Administration of L-arginine during reperfusion or its addition to cardioplegic solution has been shown to protect myocardium against ischemia-reperfusion injury. This study aimed at evaluating the role of L-arginine in ischemia-reperfusion injury when administered intraperitoneally 24 hours before cardioplegic arrest.


METHODS
Two groups of Sprague-Dawley rats (control, n = 10; and L-arginine, n = 10) were studied in an isolated buffer-perfused heart model. Both groups were injected intraperitoneally 24 hours before ischemia. Before experimentation blood samples were collected for cardiac troponin I and cGMP analysis. In the coronary effluents, cardiac troponin I, adenosine, cyclic guanosine monophosphate, and nitric oxide metabolites were assayed.


RESULTS
Before heart excision, serum cardiac troponin I concentrations were higher in the L-arginine than in the control group (0.037 +/- 0.01 versus 0.02 +/- 0.05 microg x L(-1); p < 0.05). During reperfusion, cardiac troponin I release was lower in the L-arginine than in the control group (0.04 +/- 0.01 versus 0.19 +/- 0.03 ng x min(-1); p < 0.05). The coronary flow as well as the left ventricular developed pressure were higher in the L-arginine than in the control group before ischemia and remained so throughout the experimentation.


CONCLUSIONS
These results indicate that L-arginine administered intraperitoneally 24 hours before cardioplegic arrest reduced myocardial cell injury and seems to protect myocardium against ischemia-reperfusion injury.
Yan
Y
Y
Department of Cardiovascular and Thoracic Surgery, Jean Minjoz University Hospital, Besançon, France.
Davani
S
S
Chocron
S
S
Kantelip
B
B
Muret
P
P
Kantelip
J P
JP
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D006324:Heart Arrest, Induced; D006339:Heart Rate / Q000187:drug effects; D007274:Injections, Intraperitoneal; D008297:Male; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000187:drug effects / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000473:pathology*; D009206:Myocardium / Q000473:pathology; D010477:Perfusion; D011292:Premedication; D051381:Rats; D019210:Troponin I / Q000097:blood; D016277:Ventricular Function, Left / Q000187:drug effects
D019210:Troponin I; D001120:Arginine