Interaction between prostanoids, no and vip in modulation of
duodenal alkaline secretion and motility in the rat.
Sababi, Manaf, Anneli H[umlaut]allgren, and Olof Nylander.
The Department of Physiology and Medical Biophysics, Biomedical
Center, Uppsala University, Box 572, S-751 23 Uppsala, Sweden
APStracts 3:0050G, 1996.
The relation between duodenal motility and duodenal mucosal alkaline
secretion (DMAS) was examined in anesthetized rats. The duodenum was
perfused with saline and DMAS was determined by titration. Duodenal
motility, assessed by intraluminal pressure measurements, was induced
by indomethacin and/or N-nitro-L-arginine-methyl ester (L-NAME) and
inhibited by iloprost or vasoactive intestinal peptide (VIP). Six of
66 rats showed spontaneous duodenal contractions. Basal DMAS was
higher in these rats than in those without contractions. Rats treated
with indomethacin and L-NAME prior to abdominal operation exhibited
duodenal motility postoperatively and their DMAS was higher than in
controls. Iloprost abolished both the duodenal motility increase and
increase in DMAS induced by indomethacin. L-NAME -induced motility
and increase in DMAS were antagonized by L-arginine. VIP increased
DMAS without affecting motility. VIP abolished indomethacin-induced
motility and augmented indomethacin-stimulated DMAS. VIP reduced L
-NAME-induced motility and slightly increased L-NAME-stimulated DMAS.
It is concluded that DMAS varies with duodenal motility.
Prostaglandins and NO inhibit duodenal motility, thereby indirectly
reducing DMAS. VIP may have dual effects on DMAS - an inhibitory
action mediated via smooth muscle relaxation and a stimulatory action
independent of motility.
Received 10 July 1995; accepted in final form 20 February 1996.
APS Manuscript Number G287-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 21 March 96