Expression of nitric oxide synthase in nasal polyps

Methods NP were obtained after endoscopic surgery for chronic rhinosinusitis, and separated into two categories based on eosinophil density. Nasal middle turbinates (MT) were also collected as normal controls from patients who had undergone surgery for pituitary adenomas. To identify cell types expressing isoforms of NOS, double immunostaining was performed using anti-NOS and anti-leukocyte antibodies (e.g. mast cells [MC], eosinophils, T cells and macrophages).