Possible Relation between Blood Clearance and Hepatic Uptake of ^<９９m>Tc-Phytake and Severity of Hepatic Injury in Rats

The relation between the blood clearance and hepatic uptake of ^<99m>Tc-phytate (^<99m>Tc-P) and severity of hepatic injury was investigated by using the rats induced hepatic injury with carbon tetrachloride (CC1_4), D-galactosamine (GaIN), α-naphthy1-isothiocyanate (ANIT) or DL-ethionine (EthN). After the administration of CC1_4 GaIN or ANIT, serum GPT activity increased significantly with the increase of dose level, and the degree of this increase was in the order : GaIN > CC1_4 > ANIT. However, the mild increase in serum GPT activity was observed after EthN administration. The blood clearance rate of ^<99m>Tc-P and the hepatic uptake ratio of ^<99m>Tc-P decreased with the increase of dose level after CC4_4, GaIN or ANIT administration, but significant changes were not found after EthN administration. The degree of decrease in the blood clearance rate of ^<99m>Tc-P was in the order : GaIN ≒ CC1_4 > ANIT, and the degree of decrease in the hepatic uptake ratio of ^<99m>Tc-P was in the order : GaIN ≒ CC1_4 > ANIT. These results suggest that the disorder in the hepatocytes may be one of causes for inducing the decrease in the hepatic uptake ratio of ^<99m>Tc-P, and the consequence of this decrease may induce the decrease in the blood clearance of ^<99m>Tc-P.