Loss of size-selectivity at histamine-induced exudation of plasma proteins in atopic nasal airways.
Plasma proteins occur in the airway lumen in inflammatory airway diseases. This study tests the hypothesis that airway microvascular-epithelial exudation of plasma proteins, as induced by a non-injurious inflammatory mediator, is characterized by loss of size-selectivity. Using a nasal pool-device, the nasal mucosa of 10 allergic individuals, without current disease, was sequentially exposed to saline and histamine (40 and 400 microg ml(-1)). Nasal lavage fluid and blood-levels of albumin (69 kD) and alpha2-macroglobulin (720 kD) were determined. Histamine produced concentration-dependent exudation of albumin and alpha2-macroglobulin. The albumin/alpha2-macroglobulin concentration ratio of the saline lavage fluid (baseline) was 40+/-19. However, at the histamine challenges the ratios were 25+/-3 and 22+/-2, respectively, which did not differ from that of circulating plasma (22+/-2). We conclude that there is minor and size-selective luminal entry of plasma proteins at baseline. However, at concentration-dependent exudative responses to histamine, plasma proteins enter the airway lumen without being sieved. These data indicate that inflammatory stimulus-induced extravasation, lamina propria distribution and paracellular epithelial passage of plasma occur with minimal size-selectivity. Inferentially, the full immunological capacity of plasma proteins may readily be made available at the surface of human intact airway mucosa.
Greiff
Lennart
L
Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Lund, Sweden.
Andersson
Morgan
M
Erjefält
Jonas S
JS
Svensson
Christer
C
Persson
Carl G A
CG
D000328:Adult; D001798:Blood Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006632:Histamine / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D006967:Hypersensitivity / Q000378:metabolism*; D017817:Nasal Lavage Fluid / Q000737:chemistry; D009297:Nasal Mucosa / Q000187:drug effects / Q000378:metabolism*; D010539:Permeability; D012709:Serum Albumin / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism
D001798:Blood Proteins; D012709:Serum Albumin; D000511:alpha-Macroglobulins; D006632:Histamine