Imaging of hepatic drug transporters with [131I]6-β-iodomethyl-19-norcholesterol

Sci Rep. 2019 Sep 16;9(1):13413. doi: 10.1038/s41598-019-50049-8.


We examined whether [131I]6-β-iodomethyl-19-norcholesterol (NP-59), a cholesterol analog, can be used to measure function of hepatic drug transporters. Hepatic uptake of NP-59 with and without rifampicin was evaluated using HEK293 cells expressing solute carrier transporters. The stability of NP-59 was evaluated using mouse blood, bile, and liver, and human liver S9. Adenosine triphosphate-binding cassette (ABC) transporters for bile excretion were examined using hepatic ABC transporter vesicles expressing multidrug resistance protein 1, multidrug resistance-associated protein (MRP)1-4, breast cancer resistance protein (BCRP), or bile salt export pump with and without MK-571 and Ko143. Single photon emission computed tomography (SPECT) was performed in normal mice injected with NP-59 in the presence or absence of Ko143. Uptake of NP-59 into HEK293 cells expressing organic anion transporting polypeptide (OATP)1B1 and OATP1B3 was significantly higher than that into mock cells and was inhibited by rifampicin. NP-59 was minimally metabolized in mouse blood, bile, and liver, and human liver S9 after 120 min of incubation. In vesicles, NP-59 was transported by MRP1 and BCRP. Excretion of NP-59 into bile via BCRP was observed in normal mice with and without Ko143 in the biological distribution and SPECT imaging. NP-59 can be used to visualize and measure the hepatic function of OATP1B1, OATP1B3, and BCRP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adosterol / chemistry*
  • Adosterol / pharmacokinetics
  • Animals
  • Antibiotics, Antitubercular / chemistry
  • Antibiotics, Antitubercular / pharmacology
  • Bile / metabolism*
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Liver / drug effects
  • Liver / metabolism*
  • Male
  • Mice
  • Rifampin / chemistry
  • Rifampin / pharmacology*
  • Tissue Distribution


  • Antibiotics, Antitubercular
  • Adosterol
  • Rifampin