These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effect of nociceptin in acid-evoked cough and airway sensory nerve activation in guinea pigs.
    Author: Lee MG, Undem BJ, Brown C, Carr MJ.
    Journal: Am J Respir Crit Care Med; 2006 Feb 01; 173(3):271-5. PubMed ID: 16239621.
    Abstract:
    RATIONALE: Nociceptin/orphanin FQ has been reported to inhibit capsaicin- and mechanically provoked cough in animal models, but the mechanism of this effect has not been elucidated. OBJECTIVES: The objectives of this study were to determine whether nociceptin inhibits acid-evoked cough in conscious animals and to evaluate the mechanism of this effect. METHODS: We tested the effect of nociceptin on acid-induced cough in conscious guinea pigs and acid-induced nerve activation in airway-specific vagal sensory neurons using calcium imaging techniques and the gramicidin-perforated patch clamp technique. MEASUREMENTS AND MAIN RESULTS: Nociceptin (3 mg/kg, intraperitoneal) effectively inhibited acid-evoked cough in guinea pigs by nearly 70%. Acid (pH 5) increased intracellular free calcium in acutely dissociated vagal jugular ganglionic neurons. The acid-induced increase in intracellular calcium was inhibited by a selective transient receptor potential vanilloid-1 antagonist, 5-iodo-resiniferatoxin (1 microM, approximately 80% reduction). The inhibitory effect of 5-iodo-resiniferatoxin on acid-induced increases in calcium was mimicked by nociceptin (0.1 microM). In gramicidin-perforated patch clamp recordings on airway-specific capsaicin-sensitive jugular ganglion neurons, acid (pH 5) induced two distinct inward currents. A transient current was evoked that was inhibited by amiloride and a sustained current was evoked that was inhibited by 5-iodo-resiniferatoxin. Nociceptin selectively inhibited only the sustained component of acid-induced inward current. CONCLUSION: These results indicate that the inhibitory effect of nociceptin on acid-induced cough may result from a direct inhibitory effect on peripheral C-fiber activity caused by the selective inhibition of acid-induced transient receptor potential vanilloid-1 activation.
    [Abstract] [Full Text] [Related] [New Search]