Physiol. Res. 52: 533-544, 2003

Influence of Different Oxygen Modes on the Blood Oxygen Transport and Prooxidant-Antioxidant Status during Hepatic Ischemia/Reperfusion

V. V. ZINCHUK, M. N. KHODOSOVSKY, D.A. MASLAKOV

Department of Physiology, Grodno Medical University, Grodno, Belarus

Received June 24, 2002
Accepted November 5, 2002


Summary
Oxygen supply was corrected in rabbits during the hepatic ischemia/reperfusion by means of different breathing mixtures: hypoxic (14.8 % O2+85.2 % N2), hyperoxic (78 % O2+20.2 % N2+ 1.8 % CO2), or hypercapnic (5 % CO2 in air). Hepatic ischemia was induced for 30 min by ligation of hepatic artery, reperfusion period lasted 120 min. Indices of blood oxygen transport (p50act, pCO2, pH, pO2, etc.) and prooxidant-antioxidant balance (Schiff bases, conjugated dienes, catalase, retinol, a-tocopherol) were measured in the blood and liver. The severity of reperfusion damage was evaluated by the activities of alanine and aspartate aminotransferases (ALT, AST) in the blood. Hepatic ischemia/reperfusion resulted in higher p50act in hepatic venous and mixed venous blood in all experimental groups. The changes of p50act were most marked in the hypercapnic group and were the weakest in the hypoxic group. The rise in p50act was accompanied by higher levels of lipid peroxidation products, ALT and AST in blood and liver homogenates, and by a simultaneous fall of -tocopherol and retinol concentrations, except in the hypoxic group. Catalase activity at the end of reperfusion increased under normoxia, decreased under hyperoxia or hypercapnia and did not change under hypoxia. The moderate hypoxia during reperfusion was accompanied by a better balance between the mechanisms of reactive oxygen species production and inactivation that may be observed by optimal changes in p50act and reduced the hepatic damage in this pathological condition.


Key words
Hemoglobin-oxygen affinity • Hepatic ischemia • Reperfusion • Hypoxia • Hyperoxia • Hypercapnia • Rabbits


Reprint requests
V. V. Zinchuk, Department of Physiology, Grodno Medical University, 80 Gorki st., 230015, Grodno, Belarus, e-mail: zinchuk@grsmi.unibel.by


© 2003 by the Institute of Physiology, Czech Academy of Sciences