Hepatic Asialoglycoprotein Receptor Scintigraphy Using 99mTc - Galactosylated Serum Albumin ( GSA ): Biodistribution Study in Mice with Thioacetamide - induced Hepatic Injury

Hyun, Dong Woo; Lee, Jae Tae; Chun, Kyung Ah; Lee, Sang Woo; Kim, Sung Kook; Kang, Do Young; Kwon, Young Oh; Sohn, Yoon Kyung; Lee, Kyu Bo; Chung, Joon Mo

Abstract

BACKGROUND/AIMS
Tc-DTPA-galactosylated serum albumin (GSA) is a new liver imaging agent that specifically binds to asialoglycoprotein receptor, which resides exclusively on the plasma membrane of mammalian hepatocytes. To evaluate the usefulness of hepatic scintigraphy with Tc-GSA in the assessment of hepatic function, we have investigated serial changes in organ uptakes of Tc-GSA in mice with thioacetamide-induced hepatic injury and compared to changes in histology or levels of hepatic enzymes.
MATERIALS AND METHODS
Acute hepatic injuries were induced by intraperitoneal injection of thioacetamide in ICR (Institute of Cancer Research) mice. Hepatic injuries were serially assessed by either light microscopic examination of liver slices or measurement of hepatic enzymes. The biodistribution of Tc-GSA was measured in liver and each excised organs using gamma counter.
RESULTS
Hepatic injuries in light microscopic examination were not evident at 12 hours after injection of thioacetamide but resulted in maximal centrilobular necrosis and inflammation at 24 hours. These histologic changes were progressively improved upto 72 hours. Studied hepatic enzymes were elevated at 6 hours and reached to maximal level at 24 hours after administration of thioacetamide and declined progressively after then. Hepatic uptake of Tc-GSA was lowest at 6 hours after administration of thioacetamide and serially recovered until 72 hours.
CONCLUSION
The degree in the decrease of hepatic uptake of Tc-GSA was precedent to either histologic changes or elevation of hepatic enzymes and correlated with the degree of hepatic daneges in acute hepatic injury. These findings suggest that hepatic scintigraphy using Tc-GSA can be used to detect early changes and serial assessment of hepatic function in acute hepatic injury.