Greiff, Lennart,Lunds universitet, Lund University, Medicinska fakulteten, Faculty of Medicine, Institutionen för kliniska vetenskaper, Lund, Department of Clinical Sciences, Lund, Sektion IV, Section IV, Öron-, näs- och halssjukdomar, Lund, Otorhinolaryngology (Lund)
Effects of topical platelet activating factor on the guinea-pig tracheobronchial mucosa in vivo
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.
Erjefält, Jonas,Forskargrupper vid Lunds universitet, Lund University Research Groups, Lunds universitet, Lund University, Luftvägsinflammation, Airway Inflammation and Immunology(SwePub:)
Wollmer, Per,Forskargrupper vid Lunds universitet, Lund University Research Groups, Lunds universitet, Lund University, Klinisk fysiologi, Malmö, Clinical Physiology, Malmö(SwePub:)
Sundler, Frank,Lunds universitet, Lund University, Medicinska fakulteten, Faculty of Medicine, Institutionen för experimentell medicinsk vetenskap, Department of Experimental Medical Science(SwePub:)
Persson, Carl,Lunds universitet, Lund University, Medicinska fakulteten, Faculty of Medicine, Institutionen för laboratoriemedicin, Department of Laboratory Medicine, Avdelningen för klinisk kemi och farmakologi, Division of Clinical Chemistry and Pharmacology(SwePub:)
Ingår i:Acta Physiologica ScandinavicaWiley-Blackwell0001-6772160:4, s. 387-391