IL-1β acutely increases pulmonary SP and permeability without associated changes in airway resistance and ventilation in anesthetized rats.
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.
Zhuang
Jianguo
J
Lovelace Respiratory Research Institute, Albuquerque, NM 87108, USA. jzhuang@lrri.org
Xu
Junyang
J
Zhang
Cancan
C
Xu
Fadi
F
D000280:Administration, Inhalation; D000403:Airway Resistance / Q000502:physiology*; D000758:Anesthesia; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002199:Capillary Permeability / Q000187:drug effects*; D002211:Capsaicin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005070:Evans Blue / Q000378:metabolism; D053583:Interleukin-1beta / Q000008:administration & dosage*; D008168:Lung / Q000294:innervation; D008297:Male; D036421:Nerve Fibers, Unmyelinated / Q000187:drug effects / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013373:Substance P / Q000378:metabolism*
D053583:Interleukin-1beta; D013373:Substance P; D005070:Evans Blue; D002211:Capsaicin