[Role of leptin in hepatic ischemia/reperfusion-induced hepatic injury].
OBJECTIVE; To study the changes of leptin after hepatic ischemia/reperfusion (H-I/R) and its effects on H-I/R-induced hepatic injury.


METHODS
A 70% H-I/R model of rats was established. The rats were divided into groups with different reperfusion times and sham-operation group. Radioimmunoassay was applied to measure protein levels of leptin in serum and adipose tissues of the rats. Enzyme-colorimetry was used to detect serum alanine transaminase. Hematoxylin-eosin staining and immunohistochemistry were applied to investigate pathological variations and protein expressions of leptin in livers, respectively. RT-PCR was used to detect leptin mRNA expressions in adipose tissues and livers.


RESULTS
Compared with the sham-operation group, serum leptin increased significantly in the 60 min ischemia/360 min reperfusion (I60' R360') group; protein level of leptin in adipose tissues increased significantly in the I60'R60' group; serum alanine transaminase increased significantly in all of the four reperfusion groups; protein expressions of leptin in livers increased significantly in the I60'R60' and 160'R240' groups; leptin mRNA expression in adipose tissues decreased significantly in the I60'R150' group; leptin mRNA expression in livers increased significantly in the 160'R60' group; leptin mRNA expressions in livers decreased significantly in the I60'R150', I60'R240' and I60'R360' groups. Pathological investigation showed that hepatic impairments at the early phase of H-I/R were more serious. The impairments at the later phase lessened gradually.


CONCLUSIONS
The change of leptin expressions after H-I/R may be a protective factor to withstand H-I/ R-induced hepatic injury.
Lin
Ji
J
Research Laboratory of Biochemistry, General Hospital of PLA, Beijing 100853, China.
Yan
Guang-Tao
GT
Xue
Hui
H
Hao
Xiu-Hua
XH
Zhang
Kai
K
Wang
Lu-Huan
LH
D000818:Animals; D020738:Leptin / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D020738:Leptin; D012333:RNA, Messenger