Reperfusion liver injury-induced superoxide dismutase and catalase expressions and the protective effects of N-acetyl cysteine.
OBJECTIVE
Reperfusion of the ischemic liver results in the generation of oxygen radicals. In this study, we analyzed if the mRNA and protein expressions of superoxide dismutase (SOD) and catalase increased after ischemia (I) and reperfusion (R) of the rat liver.


METHODS
Ischemia was induced by clamping off the common hepatic artery and portal vein of rats for 40 minutes, which were then reperfused for 90 minutes. Blood samples collected prior to I and after R were analyzed for hydroxyl radical (.OH), nitric oxide (NO), and alanine transferase (ALT). Liver tissues were used to analyze the SOD and catalase mRNA and protein expressions by real-time polymerase chain reaction and Western blot.


RESULTS
The results showed that this protocol resulted in elevation of the blood ALT, NO, and .OH levels (P<.001). mRNA (P<.01) and protein expressions (P<.05) of SOD and catalase were all increased. Pretreatment with antioxidant, N-acetyl cysteine, attenuated the liver injury.


CONCLUSIONS
These results indicate that reperfusion of the ischemic liver induced antioxidant enzymes expressions so that oxygen radicals are scavenged. Oxygen radical scavenger could further attenuate the I/R-induced liver injury.
Chen
C F
CF
Department of Internal Medicine, Cheng Hsin General Hospital, Taipei, Taiwan.
Hsueh
C W
CW
Tang
T S
TS
Wang
D
D
Shen
C Y
CY
Pei
J S
JS
D000111:Acetylcysteine / Q000494:pharmacology* / Q000627:therapeutic use; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D002374:Catalase / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008099:Liver / Q000293:injuries*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000201:enzymology* / Q000517:prevention & control*; D013482:Superoxide Dismutase / Q000235:genetics*
D012333:RNA, Messenger; D002374:Catalase; D013482:Superoxide Dismutase; D000410:Alanine Transaminase; D000111:Acetylcysteine