The effect of L-Arginine in experimental colitis

Abstract

SUMMARY
Inflammatory bowel diseases (IBD) include a variety of
intestinal disorders, widely distributed throughout the
human population. In recent years Nitric Oxide (NO) has
been shown to play a role in the pathophysiology of IBD
both in patients and in animal models. The aim of this study
was to examine the effect of L-arginine on the inflammatory
response ischemic colitis in an experimental rat model. The
animals used in the experiment were male Wistar rats,
weighing between 240g and 310g For the induction of
ischemic colitis, a solution of TNBS was instilled into the
rectum. Blood samples were taken and the mice were
subjected to total colectomy. To assess the severity of colitis,
haematological, biochemical and histopathological criteria
were used. For the statistical analysis of the results obtained
we used Student’s t-test, or Welch test and Mann-Whitney
test. Statistical significance between the two groups was
proved in complete blood count parameters: WBC, Hgb,
MCV, MCH and in biochemical parameters: Gluc., SGOT,
SGPT, CPK and especially MDA (Malonaldehyde), which
is a critical parameter in experimental colitis. Histological
examination of the control group (No 1) revealed epithelial
necrosis, acute infiltration of the Lamina propria consisting
of polymorphonuclear leukocytes, lymphocytes, eosinophiles
and macrophages, submucosal edema and development
of granulation and fibrous tissue of the muscular
layer. On the other hand in the L-Arginine group (No 2),
the alterations were less and not widespread in all areas as
in the control group. Some samples were almost intact and
others revealed atrophy of mucosal surface of the gastrointestinal
villae and minimal inflammation of the lamina
propria. We concluded that L-Arginine and nitric oxide
inhibitors may have a role in the treatment of inflammatory
bowel diseases in humans.
Key words: inflammatory bowel disease, IBD, L-Arginine,
ischemic colitis, nitric oxide