The ultrastructural changes of mast cells in nasal mucosa taken from patients with pollinosis during pollen season were observed by electron microscopy. The main features of degranulation were as follows: 1. swelling of granules with lower electron density; 2. disappearance of the perigranular membrane; 3. vacuoles found in cytoplasm of the mast cells. It is suggested that the mast cells in the nasal mucosa play a more important role in nasal allergy.
Humans Mast Cells