TY - JOUR
T1 - Hepatic uptake of bilirubin diglucuronide
T2 - Analysis by using sinusoidal plasma membrane vesicles
AU - Adachi, Yukihiko
AU - Roy-chowdhury, Jayanta
AU - Roy-chowdhury, Namita
AU - Kinne, Rolf
AU - Tran, Thao
AU - Kobayashi, Hiroaki
AU - Arias, Irwin M.
PY - 1990/5
Y1 - 1990/5
N2 - In order to characterize the mechanism for bilirubin transport in the liver, the uptake of bilirubin diglucuronide (BDG) into purified sinusoidal plasma membrane vesicles was investigated. BDG uptake was saturable, and was inhibited by sulfobromophthalein and unconjugated bilirubin, but was not affected by sodium taurocholate. BDG uptake was sodium-independent and was stimulated by intravesicular bilirubin or BDG (trans-stimulation). BDG transport showed strong potential sensitivity; vesicle inside-negative membrane potential created by different anion gradients inhibited BDG uptake whereas vesicle inside-positive membrane potential generated by potassium gradients and valino-mycin markedly stimulated BDG transport. These data suggest that BDG, sulfobromophthalein, and probably unconjugated bilirubin share a common transporter in liver cells which is sodium independent, membrane-potential-dependent and capable of exchange. The direction of transport in vivo may be governed by the intracellular concentration of BDG and of other yet unidentified organic an ions sharing this transporter.
AB - In order to characterize the mechanism for bilirubin transport in the liver, the uptake of bilirubin diglucuronide (BDG) into purified sinusoidal plasma membrane vesicles was investigated. BDG uptake was saturable, and was inhibited by sulfobromophthalein and unconjugated bilirubin, but was not affected by sodium taurocholate. BDG uptake was sodium-independent and was stimulated by intravesicular bilirubin or BDG (trans-stimulation). BDG transport showed strong potential sensitivity; vesicle inside-negative membrane potential created by different anion gradients inhibited BDG uptake whereas vesicle inside-positive membrane potential generated by potassium gradients and valino-mycin markedly stimulated BDG transport. These data suggest that BDG, sulfobromophthalein, and probably unconjugated bilirubin share a common transporter in liver cells which is sodium independent, membrane-potential-dependent and capable of exchange. The direction of transport in vivo may be governed by the intracellular concentration of BDG and of other yet unidentified organic an ions sharing this transporter.
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U2 - 10.1093/oxfordjournals.jbchem.a123120
DO - 10.1093/oxfordjournals.jbchem.a123120
M3 - Article
C2 - 2398040
AN - SCOPUS:0025301354
SN - 0021-924X
VL - 107
SP - 749
EP - 754
JO - Journal of Biochemistry
JF - Journal of Biochemistry
IS - 5
ER -