The effects of intestinal ischemia on colonic motility in conscious rats.
BACKGROUND
The present study aimed to examine whether and how colonic motility is affected by mild ischemia-induced intestinal injury in conscious rats through in vivo monitoring of colonic contractions, specifically with regard to the interstitial cells of Cajal (ICC) and the effect of nitric oxide (NO).


METHODS
Using miniature strain-gauge transducers, colonic motility with or without ischemia was recorded in conscious rats on the 4th, 7th, and 14th days after surgery. Histological examination for c-kit-positive cells was performed.


RESULTS
In control nonischemic rats, the number and duration of contractions (NC and DC, respectively) decreased gradually, but the mean amplitude of contractions (MC) and motility index (MI) did not change. On the 7th day, the NC in the ischemic group increased significantly when compared with that in the control group (P = 0.037). The DC in the ischemic group was lower than that in the control group; the difference was significant on the 4th day (P = 0.008). The MIs in the ischemic group were lower than those in the control group. In both groups, administration of NGnitro-L: -arginine methyl ester on the 7th day increased only the resting cecal motility. Pathological examinations revealed c-kit-positive cells in both groups.


CONCLUSIONS
Changes such as increased NC with shortened DC accompanied with decreased MI must have occurred at the ischemic site and might have been induced by an ischemic event. However, there exists a possibility that ICC and NO do not play a role in mild ischemia-induced dysmotility.
Suzuki
Makoto
M
Department of General Surgical Science, Gunma University, Graduate School of Medicine, 3-39-22 Showa, Maebashi 371-8511, Japan.
Takahashi
Atsushi
A
Toki
Fumiaki
F
Hatori
Reiko
R
Tomomasa
Takeshi
T
Morikawa
Akihiro
A
Kuwano
Hiroyuki
H
D000818:Animals; D003106:Colon / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D003243:Consciousness; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology*; D045823:Ileus / Q000209:etiology*; D007422:Intestines / Q000098:blood supply* / Q000601:surgery; D007511:Ischemia / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D011183:Postoperative Complications; D051381:Rats; D017208:Rats, Wistar
D004791:Enzyme Inhibitors; D019331:NG-Nitroarginine Methyl Ester