The effect of immunosuppression on peritoneal adhesions formation after small bowel transplantation in rats.
BACKGROUND
The reported incidence of adhesion related small bowel obstruction after abdominal organ transplantation is considerably lower than other abdominal procedures. The purpose of the study was to investigate the influence of immunosuppression on peritoneal adhesion formation after intestinal transplantation in rats.


METHODS
Four groups of rats (n = 6) underwent small bowel intestinal transplantation in syngeneic (Groups A, B) and allogeneic (Groups C, D) combinations. Groups B and D received tacrolimus immunosuppression 1 mg/kg/d. Animals were euthanized on postoperative day 7, and the total adhesion score (TAS), tissue hydroxyproline content (HPC), TGF-beta mRNA expression levels and histology were examined.


RESULTS
All of the animals in Group C showed severe histological (Grade III) acute cellular rejection. There were no histological signs of rejection in Group D. A significant reduction in TAS was observed in tacrolimus treated animals in both syngeneic and allogeneic combinations (Groups B and D), compared with controls (Groups A and C) (P < 0.001 and P < 0.01, respectively). TAS results correlated with the differences in TGF-beta levels that showed significant reduction when each immunosuppressed group was compared with its nontreated counterpart, i.e., (Groups B versus A, P < 0.05, and Groups D versus C, P < 0.01). TGF-beta levels were significantly high in the rejection group (C) and correlated with the intense adhesion formation that was demonstrated in that group. Group C was also the only group in which a significant elevation in HPC was demonstrated (P < 0.001).


CONCLUSIONS
Intense adhesion formation occurs during early posttransplant acute rejection. Postsurgical adhesion formation is significantly reduced in immunosuppressed rats after intestinal transplantation.
Wasserberg
Nir
N
Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA. nwassweberg@gmail.com
Nunoo-Mensah
Joseph W
JW
Ruiz
Philip
P
Tzakis
Andreas G
AG
D000818:Animals; D006909:Hydroxyproline / Q000032:analysis; D007165:Immunosuppression Therapy; D007421:Intestine, Small / Q000637:transplantation*; D008297:Male; D011183:Postoperative Complications / Q000517:prevention & control*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011917:Rats, Inbred Lew; D000267:Tissue Adhesions / Q000517:prevention & control*; D016212:Transforming Growth Factor beta / Q000235:genetics; D014184:Transplantation, Homologous
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D006909:Hydroxyproline