THE ROLE OF THE BLOOD OXYGEN IN PROTECTIVE MECHANISM OF ISCHEMIC PRECONDITIONING DURING HEPATIC ISCHEMIA-REPERFUSION
The role of blood oxygen in the protective mechanism of ischemic preconditioning (IPC) was investigated in rabbits during hepatic ischemia-reperfusion (HIR). Animals were divided into 2 experimental groups: in the 1st group (n = 11) hepatic ischemia (30 min) was induced by Pringle maneuver, reperfusion was lasted 120 min; in the 2nd group (n = 8) the short period of vascular clamping (10 min) and reperfusion (10 min) were performed before HIR. The parameters of blood oxygen (рО2, p50, Hb), acid-base balance (рН, рСО2, TCO2, ABE, SBE, SBC and etc.), lipid peroxidation (Schiff bases, conjugated dienes), antioxidant system (catalase, α-tocopherol), plasma transaminases (ALT, AST) and nitrite/nitrate concentration (NOx) were measured. HIR in the 1st group leads to elevation of p50, lipid peroxidation, ALT and AST accompanied by reduction of рН, TCO2, ABE, SBE, SBC, catalase activity, α-tocopherol and NOx levels. IPC significantly reduces p50, lipid peroxidation, ALT and AST simultaneously improves рН, TCO2, ABE, SBC, catalase activity, α-tocopherol and NOx levels. These findings indicate that IPC prevents oxidative stress in liver trough increased blood hemoglobin-oxygen affinity and limitation of oxygen participation in free radical processes during reperfusion.