Amelioration of liver injury by ischaemic preconditioning

Background. Ischaemic preconditioning, i.e. preparatory brief ischaemia before subsequent long ischaemia, can effectively protect the heart from ischaemia-reperfusion injury in animals. The purpose of this study was to demonstrate the same phenomenon in the liver. Methods. Using warm ischaemia-reperfusion of 70 per cent of the liver followed by resection of the non-ischaemic portion in rats, livers with 10 min of ischaemic preconditioning, i.e. 10 min of warm ischaemia and reperfusion, were compared with those that had not been subjected to such a manoeuvre. Results. At 120 min after reperfusion following 40 min of warm ischaemia, the livers with 10 min of ischaemic preconditioning had a significantly lower mean (s.d.) serum alanine aminotransferase level (492 (217) versus 1236 (695) units/l; P < 0.005) and lactic dehydrogenase level (7905 (4002) versus 15,066 (9201) units/l; P < 0.05), as well as a higher bile output (0.12 (0.03) versus 0.09 (0.04) ml per g liver; P < 0.05) and liver tissue adenosine 5'-triphosphate level (78 (13) versus 61 (11) per cent; P < 0.05) than the control livers. The necrosis rate, histologically defined as the percentage of necrotic area in given liver sections, was reduced significantly by this manoeuvre (mean (s.d.) 1.3 (1.3) versus 5.3 (1.7) per cent; P < 0.05). Conclusion. Ischaemic preconditioning exerts a protective effect on hepatic warm ischaemia-reperfusion injury. Such a manoeuvre may be useful for hepatic resection in the clinical setting.