STIMULATION OF DISPERSED NASAL POLYP CELLS BY HYPEROSMOLAR SOLUTIONS

It has been suggested that hyperosmolarity may be one of the stimuli t hat provoke exercise-induced asthma and rhinitis. We investigated whet her changes in osmolarity could result in increased levels of mediator release from nasal cells. Cells were dispersed from nasal cells. Cell s were dispersed from nasal polyps by enzymatic digestion and were inc ubated for 15 minutes with solutions of varying osmolarity obtained by the addition of mannitol to Hanks' balanced salt solution. After incu bation was performed, cell supernatants were removed, and the release of 15-hydroxyeicosatetraenoic acid, prostaglandin(2) leukotriene B-4, and fibronectin was measured. Lactate dehydrogenase was measured to as sess cell viability. Epithelial cells made up 40% to 60% of cells and mononuclear cells 40% to 65%. At 900 mOsm/kg H2O, which has been sugge sted as the osmolarity of the fluid lining the airways during exercise , we observed a significant increase (Wilcoxon W test) in the release of 15-hydroxyeicosatetraenoic acid (p<0.008), leukotriene B-4 (p<0.008 ), and prostaglandin(2) (p<0.008), but not significant increase in the release of fibronectin was seen. No significant increase was seen bet ween hydroxyeicosatetraenoic acid release, suggesting that the increas e in mediator levels was not caused by cell death.