<p><b>OBJECTIVE</b>To investigate the protective effects of
protein kinase C (PKC) and
mitogen-activated protein kinases (MAPKs) their and mechanisms in
liver ischemic preconditioning.</p><p><b>
METHODS</b>In
rat models of
liver ischemia-
reperfusion (IR) and
ischemic preconditioning (IP), the
liver function was evaluated by examining
serum alanine aminotransferase and
aspartate aminotransferase levels, and the morphological changes of the
liver cells were observed under microscope. PKC activator phorbol 12-
myristate 13-
acetate(PMA) and inhibitor chelerythrine(CHE), as well as
MEK inhibitor PD98059, were utilized to analyze the
phosphorylation of PKC and P44/42 MAPKs.</p><p><b>RESULTS</b>Compared with the control
rats, the
liver function was best protected in
rats of IP group, but not in those of IP group with PD98059 or CHE
treatment. The
rats in IR group showed improved
liver function after PMA
treatment. Similarly, the
phosphorylation of PKC and P44/42 MAPKs was correlated with the
liver function, and highly enhanced PKC and P44/42 MAPKs activity was observed in IP and IR+PMA groups, but decreased activity in IR and IP+CHE groups.</p><p><b>CONCLUSION</b>
Phosphorylation of PKC and MAPKs
plays a pivotal
role in the preservation of the
hepatocytes during IP.</p>