PT  - JOURNAL ARTICLE
AU  - Sara Neyt
AU  - Maarten T. Huisman
AU  - Christian Vanhove
AU  - Hilde De Man
AU  - Maarten Vliegen
AU  - Lieselotte Moerman
AU  - Caroline Dumolyn
AU  - Geert Mannens
AU  - Filip De Vos
TI  - In Vivo Visualization and Quantification of (Disturbed) Oatp-Mediated Hepatic Uptake and Mrp2-Mediated Biliary Excretion of <sup>99m</sup>Tc-Mebrofenin in Mice
AID  - 10.2967/jnumed.112.108233
DP  - 2013 Apr 01
TA  - Journal of Nuclear Medicine
PG  - 624--630
VI  - 54
IP  - 4
4099  - http://jnm.snmjournals.org/content/54/4/624.short
4100  - http://jnm.snmjournals.org/content/54/4/624.full
SO  - J Nucl Med2013 Apr 01; 54
AB  - Hepatic transport of 99mTc-mebrofenin through organic anion transport protein 1a and 1b (Oatp1a/1b) and multidrug resistance protein 2 (Mrp2) was investigated by small-animal SPECT. On the basis of the results, a noninvasive method to visualize and quantify disturbances in hepatic transport is proposed. Methods: Friend virus B wild-type mice (untreated, bile duct–ligated, vehicle- or rifampicin-treated) and strain-matched knockout mice unable to express the uptake transporters Oatp1a/1b (Slco1a/1b−/−/−/−) or the efflux transporter Mrp2 (Abcc2−/−) were intravenously injected with 99mTc-mebrofenin (n = 3 per group). After dynamic small-animal SPECT and short CT acquisitions, time–activity curves of the liver and of the gallbladder and intestines were obtained and correlated with direct blood samples. Results: Normal hepatobiliary clearance of 99mTc-mebrofenin was severely impaired in the bile duct–ligated animal, as evidenced by elevated hepatic tracer levels. In Slco1a/1b−/−/−/− mice, a lower area under the curve (AUC) for the liver (P = 0.014) was obtained and no activity was detected in the gallbladder and intestines. Renal rerouting was observed, along with an increase in the blood AUC (P = 0.01). Abcc2−/− mice had a higher liver AUC (P = 0.009), a delayed emergence time of 99mTc-mebrofenin in the gallbladder (P = 0.009), and a lower AUC for the gallbladder and intestines (P = 0.001). The blood curve was similar to that of wild-type mice. 99mTc-mebrofenin disposition was altered after rifampicin treatments. We observed a dose-dependent delayed time point at which tracer maximized in liver, an increased AUC for liver, and a lower AUC for gallbladder and intestines (P = 0.042, 0.034, and 0.001, respectively, highest dose). Emergence in the gallbladder occurred later (P = 0.009, highest dose), and blood AUC was higher (P = 0.006). Conclusion: The current study visualized and quantified hepatic uptake and biliary efflux of 99mTc-mebrofenin. Our results demonstrated the possibility of discriminating, on a quantitative level, between lack of functional activity of sinusoidal uptake versus that of biliary efflux transporters.