L-carnitine could not improve hepatic warm ischemia-reperfusion injury despite ameliorated blood flow.
BACKGROUND
Carnitine is applied to ameliorate ischemia-reperfusion (I/R) injury of several organs. However, application to hepatic I/R injury is not frequently reported. The aim of this study was to elucidate the effect of exogenous carnitine administration to ameliorate the warm hepatic I/R injury.


METHODS
Male Wistar rats were divided into two groups, a carnitine group (Car);100 mg/kg of l-carnitine administration and a control group (C); vehicle administration. Thirty minutes after administration, the left hepatic lobes were given 60-min ischemia and then reperfused. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), tumor necrosis factor (TNF)-alpha, and lipoperoxides (LPO) were measured. Hepatic adenosine triphosphate (ATP) concentration was also measured. The hepatic blood flow was estimated using a Laser Doppler. The presence of apoptosis in the livers was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining.


RESULTS
In group Car, the blood flow of the left hepatic lobes was better recovered during the reperfusion period than in group C (P < 0.0001). Plasma levels of ALT, AST, GLDH, and TNF-alpha at 1 h after reperfusion were not significantly different between the groups. Although there were no statistical significances, ALT, AST, and TNF-alpha levels in group Car at 24 h after reperfusion tended to be higher than in group C. Plasma LPO levels were not different between the two groups. Also hepatic ATP concentration was not different between the two groups. TUNEL positive liver cells were visible only in group Car at 24 h after reperfusion, but not in the controls.


CONCLUSIONS
Although carnitine administration improved the hepatic blood flow during the reperfusion period, we could not demonstrate a protective effect to the hepatic warm I/R injury.
Yonezawa
Kei
K
Department of Surgery, Division of Surgical Research, University of Bonn, Bonn, Germany.
Tolba
René H
RH
Wetter
Axel
A
Yamamoto
Yuzo
Y
Yamaoka
Yoshio
Y
Minor
Thomas
T
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D017209:Apoptosis; D001786:Blood Glucose / Q000032:analysis; D002331:Carnitine / Q000627:therapeutic use*; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008099:Liver / Q000098:blood supply*; D008102:Liver Circulation / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000188:drug therapy*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D001786:Blood Glucose; D014409:Tumor Necrosis Factor-alpha; D007770:L-Lactate Dehydrogenase; D000410:Alanine Transaminase; D002331:Carnitine