title: Anatomy of the Murine Hepatobiliary System: A Whole-Organ-Level Analysis Using a Transparency Method.
abstract: The biliary tract is a well-branched ductal structure that exhibits great variation in morphology among vertebrates. Its function is maintained by complex constructions of blood vessels, nerves, and smooth muscles, the so-called hepatobiliary system. Although the mouse (Mus musculus) has been used as a model organism for humans, the morphology of its hepatobiliary system has not been well documented at the topographical level, mostly because of its small size and complexity. To reconcile this, we conducted whole-mount anatomical descriptions of the murine extrahepatic biliary tracts with related blood vessels, nerves, and smooth muscles using a recently developed transparentizing method, CUBIC. Several major differences from humans were found in mice: (1) among the biliary arteries, the arteria gastrica sinistra accessoria was commonly found, which rarely appears in humans; (2) the sphincter muscle in the choledochoduodenal junction is unseparated from the duodenal muscle; (3) the pancreatic duct opens to the bile duct without any sphincter muscles because of its distance from the duodenum. This state is identical to a human congenital malformation, an anomalous arrangement of pancreaticobiliary ducts. However, other parts of the murine hepatobiliary system (such as the branching patterns of the biliary tract, blood vessels, and nerves) presented the same patterns as humans and other mammals topologically. Thus, the mouse is useful as an experimental model for studying the human hepatobiliary system.
authors.affiliation: Laboratory of Veterinary Anatomy, The University of Tokyo, Tokyo, 113 8657, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Higashiyama
authors.affiliation: Laboratory of Veterinary Anatomy, The University of Tokyo, Tokyo, 113 8657, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sumitomo
authors.affiliation: Laboratory of Veterinary Anatomy, The University of Tokyo, Tokyo, 113 8657, Japan.
authors.forename: Aisa
authors.initials: A
authors.lastname: Ozawa
authors.affiliation: Laboratory of Veterinary Anatomy, The University of Tokyo, Tokyo, 113 8657, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Igarashi
authors.affiliation: Laboratory of Veterinary Anatomy, The University of Tokyo, Tokyo, 113 8657, Japan.|College of Bioresource Sciences, Nihon University, Kanagawa, 252 0880, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Tsunekawa
authors.affiliation: Laboratory of Veterinary Anatomy, The University of Tokyo, Tokyo, 113 8657, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Kurohmaru
authors.affiliation: Laboratory of Veterinary Anatomy, The University of Tokyo, Tokyo, 113 8657, Japan.
authors.forename: Yoshiakira
authors.initials: Y
authors.lastname: Kanai
mesh_terms: D000818:Animals; D017734:Bile Ducts, Extrahepatic / Q000033:anatomy & histology*; D015415:Biomarkers / Q000378:metabolism; D001808:Blood Vessels / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D009130:Muscle, Smooth / Q000033:anatomy & histology*; D010525:Peripheral Nerves / Q000033:anatomy & histology*
chemical_list: D015415:Biomarkers
keywords: biliary tract; gallbladder; hepatic artery; liver; mouse