Transport of fluorescent chenodeoxycholic acid via the human organic anion transporters OATP1B1 and OATP1B3.
This study sought to clarify the contributions of organic anion-transporting polypeptide (OATP) 1B1 and 1B3 to the liver uptake of chenodeoxycholic acid (CDCA). We synthesized a fluorescent version of CDCA, chenodeoxychilyl-(Nepsilon-NBD)-lysine (CDCA-NBD), to characterize transporter-mediated uptake. CDCA-NBD is efficiently transported by OATP1B1 and OATP1B3 with high affinities. The Michaelis-Menten constants for CDCA-NBD uptake by OATP1B1 and OATP1B3 were 1.45 +/- 0.39 microM and 0.54 +/- 0.09 microM, respectively. By confocal laser scanning microscopy, CDCA-NBD, which is taken up by OATP1B1 and OATP1B3, was observed to localize to the cytosol. We also examined the transport of newly synthesized fluorescent bile acids. NBD-labeled bile acids, including cholic acid, deoxycholic acid, lithocholic acid, and ursodeoxycholic acid, were all transported by OATP1B1 and OATP1B3. CDCA-NBD exhibited the highest rate of transport of the five NBD-labeled bile acids examined in OATP1B1- and OATP1B3-expressing cells. Our results suggest that OATP1B1 and OATP1B3 play important roles in CDCA uptake into the liver. Fluorescent bile acids are useful tools to characterize the uptake properties of membrane transporters.
Yamaguchi
Hiroaki
H
Division of Clinical Pharmacy, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
Okada
Masahiro
M
Akitaya
Shou
S
Ohara
Hiroshi
H
Mikkaichi
Tsuyoshi
T
Ishikawa
Haruna
H
Sato
Mayumi
M
Matsuura
Masaki
M
Saga
Toshihide
T
Unno
Michiaki
M
Abe
Takaaki
T
Mano
Nariyasu
N
Hishinuma
Takanori
T
Goto
Junichi
J
D001647:Bile Acids and Salts / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D001692:Biological Transport; D045744:Cell Line, Tumor; D002635:Chenodeoxycholic Acid / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D006801:Humans; D018613:Microscopy, Confocal; D015394:Molecular Structure; D009578:Nitrobenzenes / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D027362:Organic Anion Transport Protein 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D029362:Organic Anion Transporters, Sodium-Independent / Q000235:genetics / Q000378:metabolism*; D010080:Oxazoles / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D013997:Time Factors
C511330:7-chloro-4-nitrobenz-2-oxa-1,3-diazole; D001647:Bile Acids and Salts; D009578:Nitrobenzenes; D027362:Organic Anion Transport Protein 1; D029362:Organic Anion Transporters, Sodium-Independent; D010080:Oxazoles; D002635:Chenodeoxycholic Acid