Tachykininergic mediation of viscerosensitive responses to acute inflammation in rats: role of cgrp. V[umlaut]aronique, Julia, and Bueno Lionel. Department of Pharmacology, INRA, Toulouse, FRANCE
APStracts 3:0168G, 1996.
Tachykinins, co-localized with CGRP in sensory afferences, are involved in viscerosensitive responses. We investigated the role of tachykinins and CGRP in both nociceptive and visceromotor responses to inflammation. Visceral pain was assessed by abdominal muscle contractions. Gastric emptying (GE) was evaluated after gavage with [51Cr] meal. Acetic acid (AA) or NaCl 9[EPSILON] were injected intraperitoneally before the meal. RP-67,580, SR-48,968, hCGRP(8-37), or their vehicles were injected before AA or saline. RP-67,580, SR -48,968 or their vehicles were injected before CGRP, and the mel. GR -73,632 or GR-76,349 were injected before the meal. AA inhibited GE and increased the number of abdominal contractions. RP-67,580 reduced the GE inhibition without affecting the abdominal response. SR-48,968 only reduced the AA-induced increase of abdominal contractions. h(8 -37)CGRP reduced both responses induced by AA. CGRP mimicked the effects of AA. RP-67,580 abolished CGRP-induced GE inhibition, whereas SR-48,968 only diminished visceral pain. GR-73,632 reduced GE and GR-64,349 increased abdominal response. In inflammation, NK1 and NK2 receptors mediate the GE inhibition and visceral pain respectively. These responses involve a release of CGRP.

Received 9 November 1995; accepted in final form 5 August 1996.
APS Manuscript Number G479-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996