Expression of kidney and liver bilitranslocase in response to acute biliary obstruction.
OBJECTIVE
It has been recently demonstrated that acute obstructive jaundice is associated with modifications in the renal expression and function of organic anion transporters such as Oat1, Oat3, Oatp1 and Mrp2. This study examined the expression and function of bilitranslocase in liver and kidney from rats with bile duct ligation (BDL).


METHODS
Bilitranslocase expression was evaluated in renal homogenates (H), renal basolateral plasma membranes (KBLM) and liver plasma membranes (LPM) by immunoblotting. Bilitranslocase function was studied by measuring the kinetic parameters of electrogenic bromosulfophthalein (BSP) uptake in KBLM and LPM by a spectrophotometric technique.


RESULTS
An increased abundance of bilitranslocase in KBLM without modifications in renal H and in LPM from BDL rats was observed compared with Sham rats. BDL rats showed a higher V(max) for BSP uptake in KBLM. No differences between groups were observed for Michaelis-Menten parameters in LPM.


CONCLUSIONS
The higher renal expression and function of bilitranslocase in renal basolateral membranes from rats with obstructive cholestasis might also contribute to the dramatic increase in BSP renal excretion observed in this experimental model. This would be another compensation mechanism to overcome the hepatic dysfunction in the elimination of organic anions.
Brandoni
Anabel
A
Farmacología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET, Rosario, Argentina.
Di Giusto
Gisela
G
Franca
Raffaella
R
Passamonti
Sabina
S
Torres
Adriana M
AM
D000208:Acute Disease; D000818:Animals; D001693:Biological Transport, Active / Q000502:physiology; D002570:Ceruloplasmin; D002779:Cholestasis / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D007668:Kidney / Q000201:enzymology* / Q000473:pathology; D008099:Liver / Q000201:enzymology* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar
D008565:Membrane Proteins; D002570:Ceruloplasmin; C033838:bilitranslocase