[Evaluation of hepatic blood flow using 99mTc-GSA in rats with hepatic blood flow manipulation]

Blood clearance and hepatic uptake parameters of 99mTc-DTPA-galactosyl human serum albumin (99mTc-GSA) were evaluated in two groups of rats, normal liver group and CCl4 induced chronic liver injury group. In each group, four subgroups were classified as follows: simple laparotomy (LAP), hepatic artery ligation (HAL), portal vein ligation (PVL) and both hepatic artery and portal vein ligation (HAL + PVL). 99mTc-GSA was intravenously injected (50 micrograms/100 g B.W.) to rats. Heart and liver were targetted as region of interest and time activity curves (TACs) were obtained. The blood clearance parameters (HH4 and Kd) and the hepatic uptake parameters (LHL4 and Ku) were calculated from these TACs. In normal liver group, the mean HH4 of LAP was significantly different from those of PVL and HAL + PVL. Similarly, the other three parameters (LHL4, Kd and Ku) of LAP were significantly different from those of PVL and HAL + PVL. CCl4 induced chronic liver injury group showed significant difference on all four parameters in four subgroups. Hepatic tissue blood flow rates (HTBFR) calculated by Laser Doppler flowmeter correlated well with 99mTc-GSA parameters in both groups. These results suggest that 99mTc-GSA is useful to estimate hepatic blood flow not only in rats with normal liver, but also in rats with CCl4 induced chronic liver injury.