Effects of ischemic preconditioning on cyclinD1 expression during early ischemic reperfusion in rats.
OBJECTIVE
To observe the effect of ischemic preconditioning on cyclinD1 expression in rat liver cells during early ischemic reperfusion.


METHODS
Fifty-four SD rats were randomly divided into ischemic preconditioning group (IP), ischemia/reperfusion group (IR) and sham operation group (SO). The IP and IR groups were further divided into four sub-groups (n = 6). Sham operation group (SO) served as the control group (n = 6). A model of partial liver ischemia/reperfusion was used, in which rats were subjected to liver ischemia for 60 min prior to reperfusion. The animals in the IP group underwent ischemic preconditioning twice for 5 min each time prior to the ischemia/reperfusion challenge. After 0, 1, 2, and 4 h of reperfusion, serum and liver tissue in each group were collected to detect the level of serum ALT, liver histopathology and expression of cyclinD1 mRNA and protein. Flow cytometry was used to detect cell cycle as the quantity indicator of cell regeneration.


RESULTS
Compared with IR group, IP group showed a significantly lower ALT level in 1 h to 4 h sub-groups (P < 0.05). Proliferation index (PI) indicated by the S-phase and G2/M-phase ratio [(S+G2/M)/(G0/G1+S+G2/M)] was significantly increased in IP group at 0 and 1 h (26.44 +/- 7.60% vs 18.56 +/- 6.40%, 41.87 +/- 7.27% vs 20.25 +/- 6.70%, P < 0.05). Meanwhile, cyclinD1 protein expression could be detected in IP group. But in IR group, cyclinD1 protein expression occurred 2 h after reperfusion. The expression of cyclinD1 mRNA increased significantly in IP group at 0 and 1 h (0.568 +/- 0.112 vs 0.274 +/- 0.069, 0.762 +/- 0.164 vs 0.348 +/- 0.093, P < 0.05).


CONCLUSIONS
Ischemic preconditioning can protect liver cells against ischemia/reperfusion injury, which may be related to cell proliferation and expression of cyclinD1 during early ischemic reperfusion.
Cai
Fang-Gang
FG
Department of General Surgery, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350004, Fujian Province, China. cfg453@163.com
Xiao
Jian-Sheng
JS
Ye
Qi-Fa
QF
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000032:analysis / Q000235:genetics*; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000502:physiology*; D007511:Ischemia / Q000097:blood / Q000503:physiopathology; D019194:Ischemic Preconditioning / Q000379:methods*; D008099:Liver / Q000098:blood supply* / Q000737:chemistry / Q000473:pathology; D008115:Liver Regeneration / Q000502:physiology; D008297:Male; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000097:blood / Q000235:genetics* / Q000503:physiopathology* / Q000517:prevention & control; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger; D019938:Cyclin D1; D000410:Alanine Transaminase