Evaluating the potential role of nitric oxide as a mediator of hydrostatic edema mediated intestinal contractile dysfunction.
BACKGROUND
Administration of L-nil, a selective inhibitor of inducible nitric oxide synthase (iNOS), improves ileus in an animal model of resuscitation induced intestinal edema. The purpose of this study was to elucidate the iNOS/nitric oxide (NO) signal transduction pathway in intestinal edema.


METHODS
Male Sprague Dawley rats were divided into two groups; CONTROL and RESUS+VH (edema, 80 cc/kg normal saline (resuscitation) with mesenteric venous hypertension). iNOS mRNA and protein, iNOS activity, NO tissue levels, soluble guanylyl cyclase (sGC) expression, and cyclic guanosine monophosphate (cGMP) levels were measured. As a functional endpoint, we evaluated intestinal contractile strength and frequency in L-nil treated animals.


RESULTS
Edema was associated with increased iNOS mRNA and protein expression without subsequent increases in iNOS activity or tissue NO levels. There was no significant change in sGC expression or increase in cGMP induced by edema. Administration of L-nil did not decrease edema development or preserve contractile strength, but increased contractile frequency.


CONCLUSIONS
Hydrostatic intestinal edema is not associated with increased iNOS activity or tissue NO levels. Administration of L-nil in edema increases intestinal contractile frequency. This may represent a potential mechanism for the amelioration of ileus seen with the administration of L-nil.
Shah
Shinil K
SK
Department of Pediatric Surgery, University of Texas Medical School at Houston, Houston, Texas 77030, USA.
Xue
Hasen
H
Jimenez
Fernando
F
Kots
Alexander Y
AY
Choi
Byung-Kwon
BK
Uray
Karen S
KS
Walker
Peter A
PA
Moore-Olufemi
Stacey D
SD
Velez
Natalia
N
Stewart
Randolph H
RH
Laine
Glen A
GA
Cox
Charles S
CS
D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism*; D004487:Edema / Q000378:metabolism*; D005769:Gastrointestinal Motility; D006162:Guanylate Cyclase / Q000378:metabolism; D006874:Hydrostatic Pressure; D007150:Immunohistochemistry; D007410:Intestinal Diseases / Q000201:enzymology*; D008239:Lysine / Q000031:analogs & derivatives; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction
C090663:N(6)-(1-iminoethyl)lysine; D012333:RNA, Messenger; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D008239:Lysine