The changes in peroxidase of the granules of eosinophils were examined in cells in the nasal mucous membranes of persons allergic to house dust.
There was a slight leakage of peroxidase from eosinophil granules immediately after placing an antigen-treated disc (house dust, Torii, 2560 μg/disc) on the nasal mucous membrane.
Leakage of peroxidase from the eosinophil granules into the cytoplasm, and extracellular release from some eosinophils, was greater 20 min after provocation, than at 30 sec.
There were two forms of peroxidase release from the plasma membrane. In one, the granule membrane fused with the plasma membrane and the peroxidase was released from the cell through destruction of the two fused membranes. This was considered to be active secretion. In the other form, the plasma membrane was damaged by peroxidase released from the granules into the cytoplasm. This was considered to be passive release following degeneration of the cell.