Gut Liver.  2019 Sep;13(5):569-575. 10.5009/gnl18265.

Bile Acid Transporters Are Expressed and Heterogeneously Distributed in Rat Bile Ducts

• Luo ZL
• Cheng L
• Wang T
• Tang LJ
• Tian FZ
• Xiang K
• Cui L

• KMID: 2458514
• DOI: http://doi.org/10.5009/gnl18265

Abstract

BACKGROUND/AIMS
Cholangiocytes are capable of reabsorbing bile salts from bile, but the pathophysiological significance of this process is unclear. To this end, we detected the expression and distribution of bile acid transport proteins in cholangiocytes from normal rat liver and analyzed the possible pathophysiological significance.
METHODS
Bile duct tissues of Sprague-Dawley rats were isolated by enzymatic digestion and mechanical isolation, and then divided into large and small bile duct tissues. Immunohistochemistry, real-time polymerase chain reaction and Western blotting were used to determine the expression of the apical sodium-dependent bile acid transporter (ASBT), ileal bile acid binding protein (IBABP), and basolateral organic solute transporter α (Ostα) in the biliary tract system of rats. Differences in the expression and distribution of these proteins were analyzed.
RESULTS
In cholangiocytes, ASBT and IBABP were mainly expressed in cholangiocytes of the large bile ducts, in which the expression of both was significantly higher than that in the small ducts (p<0.05). Ostα was simultaneously expressed in cholangiocytes of both the large and small bile ducts, showing no significant difference in expression between the two groups of bile ducts (p>0.05).
CONCLUSIONS
Bile acid transporters are expressed and heterogeneously distributed in rat bile ducts, indicating that bile acid reabsorption by cholangiocytes might mainly occur in the large bile ducts. These findings may help explore the physiology of bile ducts and the pathogenesis of various cholangiopathies.

Keyword

Cholangiocyte; Bile acid transporter; Heterogeneity; Cholangiopathies

MeSH Terms

Animals
Bile Acids and Salts
Bile Ducts*
Bile*
Biliary Tract
Blotting, Western
Carrier Proteins
Digestion
Immunohistochemistry
Liver
Physiology
Population Characteristics
Rats*
Rats, Sprague-Dawley
Real-Time Polymerase Chain Reaction
Bile Acids and Salts
Carrier Proteins