75Se-homocholic acid-taurine (75SeHCAT) is the first available γ-labeled bile acid, and should therefore be handled more efficiently and specifically by the liver than previous hepatoscintigraphic agents. We have measured serum and hepatic kinetics for 75SeHCAT, and compared them with those for the conventional hepatobiliary scintigraphic agent 99mTc-hepatoiminodiacetic acid, and with serum kinetics for the corresponding natural bile acid, [14C]cholic acid-taurine. We used a dynamic scintigraphic technique and serial blood sampling in 8 subjects. Initial hepatic uptake rate was identical to initial serum disappearance rate (14% dose/min) for 75SeHCAT, but significantly lower for 99mTchepatoiminodiacetic acid (6% vs. 14% dose/min, p <0.001). Hepatic transit time was shorter for 75SeHCAT (13 min vs. 22 min, p <0.02), net hepatic excretory rate was more rapid (1.4% vs. 0.8% dose/min, p <0.001), and urinary excretion was lower (1.0% vs. 9.0% dose, p <0.001). Initial and late plasma disappearance rates were significantly lower for 75SeHCAT (14.3% and 1.5% dose/min) than for [14C]cholic acid-taurine (21.3% and 2.8% dose/min, respectively), and plasma clearance was also lower (275 vs. 670 ml/min). In vitro, 75SeHCAT was bound to serum proteins more completely than [14C]cholic acid-taurine (90.4% vs. 86.5%, p75SeHCAT provides a hepatoscintigraphic agent that is handled more efficiently and specifically by the liver than the conventionally used agent 99mTc-hepatoiminodiacetic acid. It is not cleared from the serum as rapidly as [14C]cholic acid-taurine, probably due to its stronger protein binding. The clinical value of 75SeHCAT in assessing liver disease should be investigated.
|Number of pages||8|
|Publication status||Published - 1988|
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