Elsevier

Neuropeptides

Volume 29, Issue 3, September 1995, Pages 121-127
Neuropeptides

Relaxant effects of pituitary adenylate cyclase activating polypeptide (PACAP) on epithelium-intact and -denuded guinea-pig trachea: a comparison with vasoactive intestinal peptide (VIP)

https://doi.org/10.1016/0143-4179(95)90013-6Get rights and content

Abstract

The effect of pituitary adenylate cyclase activating peptide (PACAP 1–27) was examined on epithelium-intact and -denuded guinea-pig tracheal strips (GPT) and compared to vasoactive intestinal peptide (VIP) and salbutamol. PACAP (10−11−10−8 moles) induced dose-dependent relaxations of the basal tone of both epithelium-intact and -denuded GPT. PACAP was approximately three times less potent than either VIP or salbutamol in relaxing epithelium-intact GPT. The relaxant effects of both peptides and salbutamol were markedly attenuated following removal of the epithelial layer. L-NAME (10−4 M), a nitric oxide synthase inhibitor, did not affect the responses induced by either PACAP or VIP demonstrating that the relaxant effect is independent of nitric oxide synthesis. Phosphoramidon (5 × 10−6 M) potentiated the relaxant responses of epithelium-intact GPT to both PACAP and VIP but did not affect the responses of epithelium-denuded GPT. PACAP and VIP also induced relaxations of the guinea-pig upper bronchus. In addition, PACAP (10−6 M), as well as VIP, significantly inhibited the release of TxB2 induced by LTD4 (10−7 M) from chopped guinea-pig lung suggesting that this newly isolated peptide, which has 68% homology with VIP, may possess anti-inflammatory action in the lung.

References (25)

  • R. Bhogal et al.

    The effects of islet amyloid polypeptide and pituitary adenylate cyclase activating polypeptide on guinea-pig tracheal smooth muscle in vitro

    Br. J. Pharmacol.

    (1992)
  • P. Pradelles et al.

    Enzyme immunoassays of eicosanoids using acetylcholine esterase as label: An alternative to radioimmunoassay

    Anal. Chem.

    (1985)
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