Hepatobiliary excretion of biliverdin isomers and C10-substituted biliverdins in Mrp2-deficient (TR(-)) rats.
Multidrug resistance protein 2 (Mrp2) is considered the major mammalian membrane transporter of non-bile salt organic anions from liver to bile. Using Mrp2-deficient rats, we show that the protein is not essential for biliary excretion of biliverdin, its IIIalpha and XIIIalpha isomers, mesobiliverdin XIIIalpha or biliverdins bearing bulky lipophilic groups that are not reduced by biliverdin reductase in vivo. Yet, Mrp2 deficiency does retard the biliary excretion of these verdins to different degrees. The data indicate that there are Mrp2-independent mechanisms in the rat for biliary excretion of dicarboxylate organic anions related to biliverdin.
McDonagh
Antony F
AF
Division of Gastroenterology, University of California, S-357, Box 0538, San Francisco, CA 94143-0538, USA. tonymcd@itsa.ucsf.edu
Lightner
David A
DA
Kar
Ari K
AK
Norona
Wilma S
WS
D018528:ATP-Binding Cassette Transporters; D000818:Animals; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism*; D001664:Biliverdine / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism* / Q000493:pharmacokinetics; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D007536:Isomerism; D007700:Kinetics; D051381:Rats; D011911:Rats, Gunn
D018528:ATP-Binding Cassette Transporters; C423013:Abcc2 protein, rat; D002352:Carrier Proteins; C040381:mesobiliverdin; D001664:Biliverdine