Activin and activin receptor expression changes in liver regeneration in rat.
BACKGROUND
This study aimed to investigate regulatory mechanisms of hepatocyte proliferation by comparing liver regeneration of the remnant lobe after 70% partial hepatectomy (PH) and portal vein branch ligation (PBL) in rat.


METHODS
Expressions of activins betaA, betaC, and betaE and their receptors were investigated after PH and PBL. The proliferating cell nuclear antigen (PCNA) labeling index was used to monitor hepatocyte proliferation.


RESULTS
The PCNA labeling index in the regenerative lobe of PBL rats reached a peak at 48 h, a delay of 24 h compared with the remnant lobe in PH rats. In the postoperative early stage, the expression of activin betaA, betaC, and betaE mRNAs was stronger in PBL than PH. At 72 h the expression of activin receptor type IIA mRNA reached a peak in PH but was significantly lower in PBL.


CONCLUSIONS
Hepatocyte proliferation, and the regulated expression of activins and their receptors, differs during liver regeneration after PH and PBL in the rat. Thus, regulation of activin signaling through receptors is one of the factors determining liver regeneration after PH and PBL.
Takamura
Kazuhito
K
Department of Digestive Surgery, University of Tokushima, Tokushima 770-8503, Japan. c-takamura@eph.pref.ehime.jp
Tsuchida
Kunihiro
K
Miyake
Hidenori
H
Tashiro
Seiki
S
Sugino
Hiromu
H
D029404:Activin Receptors / Q000032:analysis / Q000235:genetics*; D028341:Activins / Q000235:genetics*; D000818:Animals; D015152:Blotting, Northern; D038681:Follistatin / Q000235:genetics; D007150:Immunohistochemistry; D008115:Liver Regeneration; D008297:Male; D009929:Organ Size; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
D038681:Follistatin; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D028341:Activins; D029404:Activin Receptors