“…After 20 minutes, phosphate buffered saline (PBS), histamine dihydrochloride (2 μg, 10 μg, or 50 μg) (Wako Pure Chemical Industries Ltd.) or recombinant human VEGF 165 (2 pg, 2 ng, 2 μg, or 10 μg) (PeproTech EC, Inc., London, UK) was dropped into the nasal cavities. Histamine doses were determined based on an earlier experiment,10 and VEGF doses used were decided based on the VEGF concentrations present in nasal secretions in allergic rhinitis 9. Twenty minutes after dropping PBS, histamine, or VEGF, 20‐mL saline perfusion was carried out from the heart immediately after phlebotomy by resection of the abdominal aorta.…”