Structural changes induced in rat leukemic basophils by immunological stimulus.

We have examined morphological events in RBL-2H3 basophilic leukocyte-derived cells following stimulation to secrete with specific antigen. Following stimulation, the cell surface undergoes a rapid and pronounced ruffling concomitant with an overall flattening. Secretory granules which are located in one area before stimulation becomes rapidly dispersed throughout the cytoplasm. Since secretion has been shown to be a relatively slow process in the RBL-2H3 cell line our observations suggest that ruffling and flattening precede the secretion process.