Hepatic ischemia/reperfusion injury occurs in numerous clinical situations including liver transplantation and hepatic resection. Therefore, accurate functional assessment of hepatocytes and prevention of ischemia/reperfusion injury to hepatocytes would be important. (99m)Tc-Galactosyl-human serum albumin is a liver scintigraphic agent that binds to asialoglycoprotein receptors (ASGP-R) on hepatocytes. We determined the number of ASGP-R during hypoxic conditions in primary cultured rat hepatocytes.
Methods: We used 3 durations of hypoxia (1, 2, and 3 h) for the cultured rat hepatocytes. The control incubation was performed under normoxic conditions (humidified 5% CO(2) in air) for the entire experiment. The maximal binding of (99m)Tc-galactosyl-human serum albumin (Bmax) to the hepatocytes (plasma membrane and endocytosis) and ketone body ratio (KBR) in the medium were estimated.
Results: The Bmax to hepatocytes and the KBR significantly decreased with time under the 3 different hypoxic conditions, whereas the cell counts of the hepatocytes did not decrease. Three hours after reoxygenation, the Bmax and KBR values that were decreased in the first 2 h of hypoxia reversed to control levels, but those Bmax and KBR values that were decreased after 3 h of hypoxia were irreversible.
Conclusion: We conclude that the decrease in the number of ASGP-R per hepatocyte appears to be more significant than the decrease in the number of hepatocytes. Therefore, measurement of ASGP-R may provide an accurate assessment of hepatic function in the clinical setting of hepatic injury and recovery.