Effects of soluble fiber on matrix metalloproteinase-2 activity and healing of colon anastomosis in rats given radiotherapy.
OBJECTIVE
Soluble fiber is fermented by colonic microflora yielding short-chain fatty acids (SCFAs) in the colon. We aimed to investigate the effect of oral administration of soluble fiber on healing of anastomosis and matrix metalloproteinase-2 activity in radiotherapy received colonic anastomosis.


METHODS
Eighty-four Wistar rats were divided into six groups. All rats were performed a left colonic resection with end-to-end anastomosis. Group I received rat cow. Group II received soluble fiber orally for five consecutive days preoperatively as well as 3rd and 6th days postoperatively. Group III received SCFAs via rectum for five consecutive days preoperatively. Group IV received irradiation to the pelvis at a total dose of 24 Gy on the 10th and 5th days before the operation. Group V was exposed to irradiation like the rats in Group IV and oral treatment like the rats in Group II. Group VI received irradiation like the rats in Group IV and transrectal treatment like the rats in Group III. On the 3rd and 7th postoperative days, all the rats were anesthetized to evaluate the anastomosis healing clinically, histologically and biochemically.


RESULTS
Third and 7th day bursting pressures of the rats that were fed with a normal diet and exposed to radiotherapy were significantly decreased (P<0.001). Bursting pressures of Groups V and VI on the 7th day were significantly higher than the control group's bursting pressures (P<0.05). Hydroxyproline levels of Group IV were significantly decreased (P<0.001). Following oral soluble fiber and transrectal administration of SCFAs, these low levels reached to the levels of control radiotherapy group. Matrix metalloproteinase-2 activity of all the rats that were exposed to radiotherapy was higher than the control group (P<0.001). Matrix metalloproteinase-2 enzyme levels in the Groups V and VI were lower than the ones in the Group IV (P<0.001). The histologic parameters of anastomotic healing such as epithelial regeneration, exudate, necrosis, and fibroblast levels were significantly improved by the use of oral soluble fiber and transrectal SCFAs treatment.


CONCLUSIONS
Undesirable effects of preoperative radiotherapy on mechanical, histological and biochemical parameters can be overcome by oral soluble fiber. Oral soluble fiber administration has similar positive effects like the transrectal administration of the SCFA's.
Kerem
Mustafa
M
Department of General Surgery, Medical Faculty, Gazi University, 06510 Besevler/Ankara, Turkey. mkerem@gazi.edu.tr
Bedirli
Abdulkadir
A
Karahacioglu
Eray
E
Pasaoglu
Hatice
H
Sahin
Onder
O
Bayraktar
Nilufer
N
Yilmaz
Tonguc Utku
TU
Sakrak
Omer
O
Goksel
Fatih
F
Oguz
Mehmet
M