Characterization of heparan sulfate on hepatocytes in regenerating rat liver.
OBJECTIVE
Liver regeneration occurs through interactions between the receptors on hepatocytes, including proteoglycans (PGs) and glycosaminoglycans (GAGs), and various growth factors. We investigated serial changes in GAGs, particularly heparan sulfate (HS), in proliferating hepatocytes.


METHODS
We performed 70% hepatectomy in male Wistar rats, and we then isolated hepatocytes by a collagenase perfusion method after each surgery. DNA synthesis was evaluated by measuring proliferating cell nuclear antigen (PCNA). After we had treated the hepatocytes by delipidation and digestion with actinase E, endo-beta-xylosidase, and alpha-amylase, we quantified GAGs by a carbazole-sulfuric acid method. GAGs were analyzed by ion-exchange chromatography, and changes in molecular weight of the HS component were investigated by size-fractionation HPLC.


RESULTS
Hepatocyte mitosis peaked at 24 h after the amount of GAGs was increased at 24 and 72 h after surgery. The amount of HS was slightly increased at 3 to 12 h after surgery, and then peaked at 24 h. The molecular weight of the HS declined by 12 h, but had recovered to the preoperative level by 24 h.


CONCLUSIONS
These results suggested that this HS molecule, which contained about ten disaccharide units during proliferation, may be an initiator of hepatocyte proliferation.
Kimura
Akitoshi
A
Department of Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, 036-8562, Japan.
Toyoki
Yoshikazu
Y
Hakamada
Kenichi
K
Yoshihara
Shuichi
S
Sasaki
Mutsuo
M
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004797:Enzyme-Linked Immunosorbent Assay; D006025:Glycosaminoglycans / Q000378:metabolism; D006497:Heparan Sulfate / Q000737:chemistry / Q000378:metabolism*; D006498:Hepatectomy / Q000379:methods; D022781:Hepatocytes / Q000378:metabolism*; D008115:Liver Regeneration; D008297:Male; D008938:Mitosis; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D018809:Proliferating Cell Nuclear Antigen