Effects of oral l-name during trichinella spiralis infection in
rat.
Hogaboam, C. M., S. M. Collins, and M. G. Blennerhassett.
Intestinal Disease Research Programme, and Departments of Medicine
and Pathology, McMaster University, Hamilton, Ontario, Canada
APStracts 3:0118G, 1996.
We investigated the involvement of nitric oxide in transmural jejunal
alterations induced by Trichinella spiralis (T. spiralis) infection
in rat. Rats were gavaged with either saline or T. spiralis larvae
and 1 h later, rats were orally treated with water, NG-nitro-L
-arginine methyl ester (L-NAME; 30 mg/kg), or NG-nitro-D-arginine
methyl ester (D-NAME; 30 mg/kg) on a daily basis. While not observed
in jejunum from uninfected rats, inducible nitric oxide synthase
(iNOS) mRNA was present in the mucosa and neuromuscular layers of
jejunum from T. spiralis-infected rats. On day 6, T. spiralis
-infected rats had a 6-fold decrease in transmural nitric oxide
synthase activity, an 11-fold increase in plasma nitrite and a 7-fold
elevation in transmural MPO activity compared to uninfected controls.
Intestinal smooth muscle cell hyperplasia and hypertrophy were only
detected in the infected rats. L-NAME, but not D-NAME treatment, of
infected rats for 6 days caused a pronounced increase in transmural
iNOS mRNA expression, coinciding with significantly increased mucosal
nitric oxide synthase activity. T. spiralis numbers in L-NAME-treated
rats were significantly lower compared to the other two infected
groups although L-NAME had no direct effect on T. spiralis viability
in vitro. Further, L-NAME treatment significantly reduced plasma
nitrite and jejunal MPO, but not intestinal smooth muscle cell
hyperplasia or hypertrophy. In contrast, D-NAME treatment of infected
rats significantly enhanced intestinal smooth muscle hyperplasia and
hypertrophy. Taken together, these results suggest that alterations
in the T. spiralis-infected jejunum are mediated, in part, by a
suppression of nitric oxide synthase activity in the inflamed
jejunum.
Received 24 February 1995; accepted in final form 5 February
1996.
APS Manuscript Number G82-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 June 96