Effects of topical platelet activating factor on the guinea-pig tracheobronchial mucosa in vivo

Summary, in English

Platelet activating factor (PAF) has been reported to produce a variety of airway effects including epithelial damage and increased airway-lung absorption of hydrophilic tracers. The present study examines effects of PAF on the guinea-pig tracheobronchial mucosa in vivo. Vehicle with and without PAF (4.0 and 8.0 nmol) was superfused onto the tracheobronchial mucosa. The levels of 125I-albumin, previously given intravenously, were determined in tracheobronchial lavage fluids as an index of mucosal exudation of plasma. The mucosa was also examined by scanning electron microscopy. In separate animals, 99mTc-DTPA (a low molecular weight, 492 Da, hydrophilic tracer) was superfused onto the mucosal surface through an oro-tracheal catheter, together with vehicle or PAF (8.0 nmol). A gamma camera determined the disappearance rate of 99mTc-DTPA from the airways as an index of mucosal absorption. PAF produced dose-dependent mucosal exudation of plasma up to 20-fold greater than control (P < 0.001). However, PAF did not damage the epithelium and the absorption ability of the airway mucosa was unaffected. The results, in contrast to previous reports, suggest that PAF may not readily damage the airway mucosa even at large exudative doses of the agent. The present finding support the view that the plasticity of the epithelial junctions allows the creation of valve-like paracellular pathways for unidirectional clearance of extravasated plasma into the airway lumen. We suggest that endogenous PAF may participate in first line respiratory defence reactions by causing lumenal entry of bulk plasma without harming the epithelium.

• Författare: Lennart Greiff; I Erjefalt; Jonas Erjefält; Per Wollmer; Frank Sundler; Carl Persson
• Avdelning/ar: Öron-, näs- och halssjukdomar, Lund; Luftvägsinflammation; Klinisk fysiologi och nuklearmedicin, Malmö; Institutionen för experimentell medicinsk vetenskap; Avdelningen för klinisk kemi och farmakologi
• Publiceringsår: 1997
• Språk: Engelska
• Sidor: 387-391
• Publikation/Tidskrift/Serie: Acta Physiologica Scandinavica
• Volym: 160
• Issue: 4
• Länkar: http://dx.doi.org/10.1046/j.1365-201X.1997.00183.x
• Dokumenttyp: Artikel i tidskrift
• Förlag: Wiley-Blackwell
• Ämne: Immunology in the medical area; Radiology, Nuclear Medicine and Medical Imaging; Medicinal Chemistry; Cell and Molecular Biology; Otorhinolaryngology; Pharmacology and Toxicology
• Nyckelord: ultrastructure; plasma exudation; inflammation; absorption; airway
• Status: Published
• Forskningsgrupp: Airway Inflammation and Immunology; Clinical Physiology, Malmö
• ISBN/ISSN/Övrigt: ISSN: 0001-6772