Involvement of vasoactive intestinal polypeptide in gastric reflex relaxation

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Abstract

We have previously presented evidence for a non-adrenergic, vagally mediated colono-gastric inhibitory reflex induced by distension of the colon. We also found that pain stimulation by putting pressure on a testicle induced a pronounced gastric relaxation mediated by both adrenergic and vagal non-adrenergic fibers in anesthetized rats. Previous in vitro studies by other workers have strongly indicated that vasoactive intestinal polypeptide (VIP) is a neural mediator of gastric relaxation. The aim of the present in vivo study was to investigate, in anesthetized rats, whether VIP is involved in the gastric reflex relaxation induced by colonic distension and pain stimulation. A volumetric method was used to monitor changes in gastric volume. Gastric reflex relaxation following colonic distension was significantly and markedly inhibited by VIP antiserum as compared to the control relaxation before administration of the antiserum. Non-immunized control serum did not significantly influence gastric relaxation caused by colonic distension. Pain-induced gastric relaxation was moderately but significantly reduced after the administration of VIP antiserum but not after control serum. The selective β2-adrenoceptor agonist, salbutamol, induced a pronounced gastric relaxation of the same magnitude before and after the administration of VIPantiserum. VIP antiserum changed the pattern of gastric motility by inducing a specific type of gastric contraction appearing spontaneously or in response to colonic distension. A close intra-arterial injection of VIP induced gastric relaxation and inhibition of phasic gastric contractions. The present results in the rat suggest that VIP or a VIP-like peptide is involved in gastric reflex relaxation induced by colonic distension and pain stimulation.

References (29)

  • F.A. De Beurme et al.

    Influence of alpha-chymotrypsin and trypsin on the non-adrenergic non-cholinergic relaxation in the rat gastric fundus

    Br. J. Pharmacol.

    (1987)
  • F.A. De Beurme et al.

    Vasoactive intestinal polypeptide as a possible mediator of relaxation in the rat gastric fundus

    J. Pharm. Pharmacol.

    (1988)
  • K.M. Desai et al.

    Involvement of nitric oxide in the reflex relaxation of the stomach to accomodate food or fluid

    Nature

    (1991)
  • K.M. Desai et al.

    Nitroxergic nerves mediate vagally induced relaxation in the isolated stomach of the guinea pig

  • Cited by (0)

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