TY - JOUR
T1 - Cloning of the dog bile salt export pump (BSEP; ABCB11) and functional comparison with the human and rat proteins
AU - Yabuuchi, Hikaru
AU - Tanaka, Kenji
AU - Maeda, Miyako
AU - Takemura, Masaaki
AU - Oka, Masaki
AU - Ohashi, Rikiya
AU - Tamai, Ikumi
PY - 2008
Y1 - 2008
N2 - The dog bile salt export pump (BSEP; ABCB11) was cloned and expressed in a Sf9 insect cell system. The deduced amino acid sequence encodes a 1325-amino-acid protein, which shows 89.4% and 80.2% homology with human BSEP and rat Bsep, respectively. The transcript of the dog Bsep gene was detected at a high level in liver, but not other tissues, by quantitative RT-PCR. The BSEP-expressing membrane vesicles isolated from Sf9 cells exhibited saturable uptake of [3H]taurocholic acid with Michaelis constants (Km) of 33.7, 22.2 and 19.9 μM for the dog, rat and human transporters, respectively. The uptake of [3H]taurocholic acid by all three transporters was significantly inhibited by troglitazone, glibenclamide, and other several inhibitors, while pravastatin inhibited dog Bsep and human BSEP, but not rat Bsep at 100 μM. The IC50 of troglitazone for dog Bsep, human BSEP, and rat Bsep were 32, 20, and 60 μM, and those of pravastatin were 441, 240 and > 1,000 μM, respectively. In conclusion, while dog Bsep shows similar ATP-dependent bile acid transport characteristics to human BSEP and rat Bsep, there is a species difference in affinity for drugs such as pravastatin and troglitazone.
AB - The dog bile salt export pump (BSEP; ABCB11) was cloned and expressed in a Sf9 insect cell system. The deduced amino acid sequence encodes a 1325-amino-acid protein, which shows 89.4% and 80.2% homology with human BSEP and rat Bsep, respectively. The transcript of the dog Bsep gene was detected at a high level in liver, but not other tissues, by quantitative RT-PCR. The BSEP-expressing membrane vesicles isolated from Sf9 cells exhibited saturable uptake of [3H]taurocholic acid with Michaelis constants (Km) of 33.7, 22.2 and 19.9 μM for the dog, rat and human transporters, respectively. The uptake of [3H]taurocholic acid by all three transporters was significantly inhibited by troglitazone, glibenclamide, and other several inhibitors, while pravastatin inhibited dog Bsep and human BSEP, but not rat Bsep at 100 μM. The IC50 of troglitazone for dog Bsep, human BSEP, and rat Bsep were 32, 20, and 60 μM, and those of pravastatin were 441, 240 and > 1,000 μM, respectively. In conclusion, while dog Bsep shows similar ATP-dependent bile acid transport characteristics to human BSEP and rat Bsep, there is a species difference in affinity for drugs such as pravastatin and troglitazone.
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U2 - 10.1002/bdd.629
DO - 10.1002/bdd.629
M3 - Article
C2 - 18985798
AN - SCOPUS:58749099991
SN - 0142-2782
VL - 29
SP - 441
EP - 448
JO - Biopharmaceutics and Drug Disposition
JF - Biopharmaceutics and Drug Disposition
IS - 8
ER -