Neuroendocrine-immune modulation may be useful for allograft-specific immunosuppression in small bowel transplantation.
OBJECTIVE
The authors have previously demonstrated that the neuropeptide bombesin (BBS) prevented allograft mucosal atrophy under tacrolimus (TRL) immunosuppression for rats small bowel transplantation (SBT). The present study investigated whether BBS had immunosuppressive effects on small bowel allografts.


METHODS
Allogeneic SBT was performed heterotopically in rats (n = 12) that received daily administration of 0.1 mg/kg/d TRL from postoperative day 0 to day 14. Rats divided into two groups of six rats each were administered BBS or normal saline as a control. Biopsy of the allograft was performed from the stomal site on postoperative days 6, 10, and 14. The state of the graft mucosal villi was evaluated by H & E staining and TUNEL immunohistochemistry.


RESULTS
By postoperative day 14, extensive mucosal destruction accompanied by heavy transmural cellular infiltration had developed in the control group. Lymphocytes and plasma cells infiltrated the lamina propria of the allograft without the distorting villous architecture in the BBS group. The TUNEL index of graft mucosa in the control group was 1.26% +/- 0.37% (mean +/- SD) and that in the BBS group, 0.59% +/- 0.20%, respectively (p < .001).


CONCLUSIONS
This study demonstrated an immunosuppressive effect of bombesin on transplanted allografts, which might dramatically reduce the dose of TRL required for postoperative immunosuppression.
Kimura
O
O
Children's Research Hospital, Kyoto Prefectural University of Medicine, 465 Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. osamu@koto.kpu-m.ac.jp
Higuchi
K
K
Furukawa
T
T
Kinoshita
H
H
Chujo
S
S
Go
S
S
Iwai
N
N
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D005998:Glycine / Q000378:metabolism; D007408:Intestinal Absorption / Q000502:physiology*; D007421:Intestine, Small / Q000637:transplantation*; D007700:Kinetics; D008297:Male; D023421:Models, Animal; D009490:Neurosecretory Systems / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D014184:Transplantation, Homologous / Q000276:immunology*
D000596:Amino Acids; D005998:Glycine