Observations on the fine structure of giant mast cells produced by microwave radiation of the peritoneal fluid

Summary An electron microscopic examination of the fine structure of giant mast cells in the peritoneal fluid of the rat was made. The giant mast cells were produced by irradiating rats with a microwave apparatus generating energy of a frequency of 2,425±25 megacycles.The most obvious features of the giant mast cell appeared to be abundant swelling of the cytoplasm, which increased the distance between the granules, and the partial disappearance of the granules. Disruption of the mast cells, with escape of the granules, was not observed. Whether the formation of the giant mast cells is a reversible process or not cannot be answered on the basis of the present study.It is a pleasure to acknowledge the skilful assistance of Miss Tellervo Huima and Mr. Mauri Nyholm, M. Sc.This study is supported by the PAULO Foundation.