Ischaemic preconditioning of the liver: a preliminary study.
BACKGROUND
A phenomenon of 'preconditioning' exists for the heart, but has not been described for the liver. This study was undertaken to determine whether a brief episode of ischaemia (3 or 5 min) followed by a short reperfusion time (5 or 10 min) would precondition the liver to reduce subsequent injury from prolonged ischaemia (30 to 90 min).


METHODS
Male Wistar rats were allocated into five control (no preconditioning) and five preconditioned groups, each having a liver resection. The preconditioning times were 3 min ischaemia followed by 5 min reperfusion with a prolonged ischaemia of 60 or 90 min for the first two groups, and 5 min ischaemia followed by 10 min reperfusion with prolonged ischaemia times of 30 or 45 min for the other three groups.


RESULTS
Of rats resected with 3-5-60 min time sequence designed to assess survival, 9/10 died. However 9/10 died also in the matching control group with 60 min ischaemia. With a 5-10-45 min sequence, 9/10 survived more than 24 h in the preconditioned group and 1/10 in the non-preconditioned controls. With a 5-10-30+ sequence designed to measure liver function tests, the prothrombin time was significantly improved; bilirubin, serum alkaline phosphatase and the alanine aminotransferase improved but these did not reach significance.


CONCLUSIONS
A brief episode of ischaemia followed by an episode of reperfusion before a prolonged period of ischaemia ameliorated the effects of ischaemia-reperfusion injury in a rat liver resection model. If hepatic preconditioning is confirmed in humans, ischaemic preconditioning will have an important role for all liver surgery.
Hardy
K J
KJ
Department of Surgery, Austin and Repatriation Medical Centre, Heidelberg, Victoria, Australian.
McClure
D N
DN
Subwongcharoen
S
S
D000818:Animals; D006801:Humans; D019194:Ischemic Preconditioning / Q000379:methods*; D008099:Liver / Q000098:blood supply* / Q000473:pathology / Q000503:physiopathology; D008111:Liver Function Tests; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000517:prevention & control*; D015996:Survival Rate