AJP - Gastrointestinal and Liver Physiology, Vol 261, Issue 1 145-G151, Copyright © 1991 by American Physiological Society
Radiation and indomethacin effects on morphology, prostaglandins, and motility in dog jejunum
R. W. Summers, C. E. Glenn, A. J. Flatt and A. Elahmady
Department of Internal Medicine, Veterans Administration Medical Center, Iowa City, Iowa.
Irradiation can have a profound effect on intestinal motor activity.
Previous studies have suggested that prostaglandins may play some role in
radiation-induced enteritis. The present study investigated the effects of
abdominal X-irradiation with or without indomethacin treatment on jejunal
myoelectric activity and prostaglandin synthesis by measuring the
prostaglandin content of mesenteric arterial and venous plasma and in the
intestinal lumen in dogs. After X-irradiation, venous concentrations and
arteriovenous concentration differences of prostaglandin (PG)E2, PGF2
alpha, and 6-keto-PGF1 alpha increased markedly. The increased venous
concentrations were in part attributable to increased mucosal and/or
submucosal synthesis by inference from increased concentrations of these
metabolites assayed from the jejunal lumen. Irradiation produced
histological damage to the mucosa and submucosa and abnormalities in the
migrating motor complex, jejunal slow waves, and a decrease in spike burst
activity. Inhibition of prostaglandin synthesis by treating the animals
with indomethacin reduced the severity of illness, the histological injury,
and changes in myoelectric activity induced by irradiation. Such treatment
should be evaluated further to treat patients exposed to large doses of
irradiation.
