Lipopolysaccharide-Induced Airway Hyporeactivity to Methacholine in Guinea Pigs In Vivo Is Absent in the Isolated, Perfused Trachea In Vitro

Details

• Personal Author:
  Fedan, Jeffery S. ; Johnston RA ; Olson SG
• Description:
  This study examined the effects of lipopolysaccharide (LPS)-treatment (4 mg/kg, i.p., 18 hr post-exposure) on guinea pig reactivity to methacholine (MCh) in vivo and in vitro. In vivo airway reactivity to MCh was measured by placing conscious, guinea pigs in a two-chamber whole body plethysmograph for measuring specific airway resistance (SRaw) and exposing them to increasing concentrations of MCh aerosol. In LPS-treated animals, the basal SRaw was increased compared to that in the saline injected control animals. In addition, the LPS-treated animals were hyporeactive to inhaled MCh. Airway reactivity in vitro was measured using the isolated, perfused trachea preparation to permit MCh addition separately to the serosal (extraluminal; EL) or mucosal (intraluminal; IL) surfaces; because of the epithelium, EL reactivity to MCh is greater than IL reactivity. In epithelium-intact tracheas there was no difference in the EC50 values for contraction to EL and IL MCh between control- and LPS-treated guinea pigs. In epithelium-denuded tracheas where the difference between EL and IL reactivity was abolished, LPS-treatment had no effect on reactivity to MCh. These results suggest that the hyporeactivity observed in vivo does not involve the trachea or the mechanism(s) is lost in vitro. [Description provided by NIOSH]
• Subjects:
  Aerosols Animals Environmental Exposure Laboratories Methacholine Compounds Occupational Health Respiratory System Safety
• Keywords:
  Airway Resistance Animal Studies Exposure Levels In Vitro Studies In Vivo Studies Laboratory Animals Methacholines
• ISSN:
  0892-6638
• Document Type:
  Text
• Genre:
  Abstract or Summary ; Proceedings
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  14
• Issue:
  8
• NIOSHTIC Number:
  nn:20020971
• Citation:
  FASEB J 2000 May; 14(8):A1497
• Federal Fiscal Year:
  2000
• Peer Reviewed:
  False
• Source Full Name:
  The FASEB Journal
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:161c6af39a1537626e4a4c4042bac4544c56e6d71b4c6dd68e2ab2ad4aee22f2856a97836bfa406453479aa317c443e916175c63c32eeedcf297d644aee53eba
• Download URL:
  https://stacks.cdc.gov/view/cdc/198577/cdc_198577_DS1.pdf
• File Type:
  [PDF - 448.54 KB ]