IL-1β acutely increases pulmonary SP and permeability without associated changes in airway resistance and ventilation in anesthetized rats

Respir Physiol Neurobiol. 2011 Jan 31;175(1):12-9. doi: 10.1016/j.resp.2010.08.002. Epub 2010 Aug 6.

Abstract

Bronchopulmonary C-fibers (PCFs), when activated, promote substance P (SP) release, increase microvascular leak, and produce bronchoconstriction and apnea. IL-1β administered systemically or locally into the pulmonary parenchyma stimulates PCFs. Thus, we tested whether right atrial bolus injection or aerosol inhalation of IL-1β, to mainly stimulate PCFs, would acutely affect pulmonary SP level and vascular permeability, airway resistance (R(L)), and ventilation in anesthetized rats. Our results showed that 30min after IL-1β injection (2-6 μg kg⁻¹), SP levels and Evans blue extravasation in bronchoalveolar lavage fluid were markedly increased and these responses were eliminated or largely reduced in neonatal capsaicin-treated rats. In contrast, neither injection nor inhalation of IL-1β (5-15 μg ml⁻¹) significantly altered R(L) and ventilation. Additionally, the capsaicin-evoked (4 μg kg⁻¹, i.v.) apneic response was unaffected by IL-1β treatment. Our data suggest that IL-1β, as administered in this study, can acutely increase pulmonary SP and vascular permeability, likely via stimulating PCFs, with little impact on R(L) and ventilation.

MeSH terms

  • Administration, Inhalation
  • Airway Resistance / physiology*
  • Anesthesia*
  • Animals
  • Bronchoalveolar Lavage Fluid / chemistry
  • Capillary Permeability / drug effects*
  • Capsaicin / pharmacology
  • Dose-Response Relationship, Drug
  • Evans Blue / metabolism
  • Interleukin-1beta / administration & dosage*
  • Lung / innervation
  • Male
  • Nerve Fibers, Unmyelinated / drug effects
  • Nerve Fibers, Unmyelinated / physiology
  • Pulmonary Ventilation / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Substance P / metabolism*

Substances

  • Interleukin-1beta
  • Substance P
  • Evans Blue
  • Capsaicin