Expression of NCAM in activated portal fibroblasts during regeneration of the rat liver after partial hepatectomy.
In the portal tract of the regenerating liver after partial hepatectomy, vascular and bile ductular remodeling takes place in response to the portal hyperdynamic state and parenchymal hyperplasia. In order to reveal phenotypical changes in the portal fibroblasts, we immunohistochemically investigated neural cell adhesion molecules (NCAM) and alpha smooth muscle actin (alphaSMA) expression and the ultrastructural changes in them during liver regeneration. In the control rat liver, portal fibroblasts were negative for both NCAM and alphaSMA. They became positive for both markers two days after partial hepatectomy, increased in staining intensity, reached a maximum at three to four days, then decreased, being still clearly positive at 14 days. Under an electron microscope, portal fibroblasts from the regenerating liver had larger amounts of cytoplasm and rough endoplasmic reticulum than those from the control liver; thus they might be activated. Additionally, periportal hepatic stellate cells in the regenerating liver were activated with alphaSMA, but without NCAM. The present study has demonstrated that portal fibroblasts express NCAM and alphaSMA in the regenerating liver after partial hepatectomy via transformation into myofibroblasts following reconstruction of the portal tracts.
Nakatani
Kazuki
K
Department of Anatomy, Graduate School of Medicine, Osaka City University, Osaka, Japan. kazuki@med.osaka-cu.ac.jp
Tanaka
Hisao
H
Ikeda
Kazuo
K
Sakabe
Masahide
M
Kadoya
Hirokazu
H
Seki
Shuichi
S
Kaneda
Kenji
K
Nakajima
Yuji
Y
D000818:Animals; D001659:Biliary Tract / Q000098:blood supply / Q000166:cytology / Q000294:innervation / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D006498:Hepatectomy; D015151:Immunoblotting; D007150:Immunohistochemistry; D008099:Liver / Q000601:surgery / Q000648:ultrastructure; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D009412:Nerve Fibers / Q000378:metabolism; D019006:Neural Cell Adhesion Molecules / Q000096:biosynthesis* / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar
D019006:Neural Cell Adhesion Molecules