A study of time window for oxidative stress associated with myocardial ischemia and reperfusion.
OBJECTIVE
To investigate the time window for oxidative stress occurred in myocardial tissue and associated with reperfusion.


METHODS
Thirty nine conscious rabbits were subjected to 0.5 hours (h) of myocardial ischemia and reperfusion for 0 h, 6 h, 24 h and 72 h, respectively, and nine rabbits served as controls. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-px) and myeloperoxidase (MPO), and contents of GSH and malondyaldehyde (MDA) were measured in myocardial tissues taken from ischemic non-necrotic area (INNA), ischemic necrotic area (INA) and non-ischemic area (NIA), respectively.


RESULTS
The antioxidant status of INNA was weakened at 6th h, 24th h, and 48th h of reperfusion. Activities of Mn-SOD and Cu-Zu-SOD returned to normal value at 72nd h of reperfusion, but GSH-px activity and GSH content remained in lower value. MDA content had a marked increase at 6th h, 24th h, 48th/h and 72nd h of reperfusion. MPO activity had a progressive increase after reperfusion, with its peak value at 48th h, and PMN accumulation occurred mostly in necrotic zone and its outer board zone. A mild oxidative stress also occurred in non-ischemic tissue, but without obvious neutrophils infiltration.


CONCLUSIONS
The time window for oxidative stress associated with myocardial ischemia and reperfusion lasts for at least 72 h, and PMN infiltration is one of the most important factors of delayed myocardial reperfusion injury.
Zhao
X
X
Department of Cardiology, Changzheng Hospital, Shanghai.
Fu
W
W
Yuan
W
W
Wu
Z
Z
Yang
Z
Z
D000818:Animals; D005979:Glutathione Peroxidase / Q000378:metabolism; D066298:In Vitro Techniques; D008315:Malondialdehyde / Q000378:metabolism; D017202:Myocardial Ischemia / Q000378:metabolism*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism*; D009504:Neutrophils / Q000502:physiology; D018384:Oxidative Stress; D009195:Peroxidase / Q000378:metabolism; D011817:Rabbits; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
D008315:Malondialdehyde; D009195:Peroxidase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase