Experimental study on hepatic reinnervation after orthotopic liver transplantation in rats.
OBJECTIVE
The present study examined whether extrinsic hepatic reinnervation occurred after orthotopic liver transplantation (OLT) in rats.


METHODS
Inbred male Lewis rats were the recipients and females the donors. Tissue specimens were obtained postoperatively from the stump of a recipient's hepatoduodenal ligament (A), and the hepatic hilus (B) and peripheral parenchyma (C) of liver allografts, up to 6 months post-operation. Specimens were subjected to immunohistochemical examination using growth-associated protein (GAP)-43 as an axonal marker and transmission electron microscopy (TEM) for observing regenerating axons, as well as the polymerase chain reaction assay to detect the rat sex-determining region Y (SRY) protein gene of the regenerating nerves.


RESULTS
At site A, GAP-43-positive nerve axons were identified from day 1 to 1 month post-OLT and SRY protein genes were expressed at and after 3 days post-OLT. At site B, GAP-43-positive axons were observed between 3 days and 1 month, and SRY protein genes were detected at 1 month post-OLT and thereafter. TEM confirmed the presence of regenerating axons at and after 3 days post-OLT.


CONCLUSIONS
The results demonstrated that regenerating nerve fibers originating from the recipients reinnervated liver allografts. This extrinsic innervation occurred shortly after OLT, and most likely terminated after about 3 months.
Sakamoto
Izumi
I
Department of Surgery, Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan. idumisa@med.kitasato-u.ac.jp
Takahashi
Tsuyoshi
T
Kakita
Akira
A
Hayashi
Izumi
I
Majima
Masataka
M
Yamashina
Shohei
S
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D019922:GAP-43 Protein / Q000378:metabolism; D015870:Gene Expression; D007150:Immunohistochemistry; D008099:Liver / Q000294:innervation* / Q000503:physiopathology; D016031:Liver Transplantation; D008297:Male; D008854:Microscopy, Electron; D009416:Nerve Regeneration; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D011184:Postoperative Period; D051381:Rats; D011917:Rats, Inbred Lew; D051876:Sex-Determining Region Y Protein; D013997:Time Factors; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D019922:GAP-43 Protein; D009687:Nuclear Proteins; D051876:Sex-Determining Region Y Protein; C497747:Sry protein, rat; D014157:Transcription Factors