title: Features of acute liver congestion on gadoxetate disodium-enhanced MRI in a rat model: Role of organic anion-transporting polypeptide 1A1.
abstract: OBJECTIVE
  To evaluate the features of hepatic congestion on gadoxetate disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and the mechanisms responsible for the radiological findings in a rat model of partial liver congestion.
  
  
  METHODS
  A conventional T1 -weighted spin-echo sequence of the liver was performed using a 1.5T magnetic resonance imager with an 80-mm magnetic aperture for animal studies. We induced regional congestion using partial left lateral hepatic vein ligation (n = 5) and evaluated the following in both congestive liver (CL) and noncongestive liver (non-CL): 1) chronological changes in the relative enhancement (RE) up to 60 minutes after Gd-EOB-DTPA administration, and 2) mRNA and protein expression of rat organic anion transporting protein 1a1 (Oatp1a1).
  
  
  RESULTS
  The RE in the CL reached a small peak (18%) at 5 minutes, corresponding to approximately half of the value observed in the non-CL, then slowly decreased in a linear manner thereafter. The degree of RE in the CL was significantly lower than that in the non-CL for up to 30 minutes (P < 0.05). An immunohistological examination showed that Oatp1a1 protein expression was downregulated in the CL. The mRNA level of Oatp1a1 in the CL was significantly upregulated, compared with that in control rat liver (P = 0.046), whereas no significant difference was observed between the CL and the non-CL (P = 0.698).
  
  
  CONCLUSIONS
  The reduced signal intensity in the CL on Gd-EOB-DTPA-enhanced MRI could be explained by the decreased uptake of Gd-EOB-DTPA via Oatp1a1 protein in the congestive area.
authors.affiliation: First Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Shimizu
authors.affiliation: First Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: First Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Motoyama
authors.affiliation: First Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakai
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamada
authors.affiliation: Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yoshizawa
authors.affiliation: Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Momose
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Masumi
authors.initials: M
authors.lastname: Kadoya
authors.affiliation: First Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Miyagawa
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D001646:Bile / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry*; D017352:Echo-Planar Imaging; D019786:Gadolinium DTPA / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D029362:Organic Anion Transporters, Sodium-Independent / Q000096:biosynthesis*; D027701:Organic Cation Transport Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D019097:Spin Trapping
chemical_list: D003287:Contrast Media; C000609070:Oatp1a1 protein, rat; D029362:Organic Anion Transporters, Sodium-Independent; D027701:Organic Cation Transport Proteins; C073590:gadolinium ethoxybenzyl DTPA; D000255:Adenosine Triphosphate; D019786:Gadolinium DTPA
keywords: Gd-EOB-DTPA-enhanced MR imaging; Oatp1a1; partial liver congestion; rat