X-RAY-MICROANALYSIS OF RAT MAST-CELLS STIMULATED WITH COMPOUND-48 80 IN COMBINATION WITH QUICK-FREEZING METHOD/

X-ray microanalysis was performed on rat mast cells prepared by quick- freezing, cryosectioning and freeze-drying (QF-FD) method, or quick-fr eezing and freeze-substitution (QF-FS) method. Peritoneal cells includ ing mast cells were stimulated with compound 48/80 for 0, 10 or 30 s a t 17 degrees C, and the mast cells stimulated for 30 s started exocyto sis. In X-ray spectra of the QF-FD specimen, mast cells stimulated for 10 s increased their levels of phosphorus, sodium and chlorine in the intergranular cytoplasm prior to exocytosis, and kept this increase u ntil 30 s after stimulation. In the QF-FS specimen, where soluble elem ents were removed, peaks of phosphorus, sulphur and potassium could be detected as elements in X-ray spectra. Phosphorus increased and potas sium decreased in intergranular cytoplasm of mast cells stimulated for 10 s, and these changes became more obvious after 30 s. However, supp lemental increase of other cations such as sodium could not be detecte d in the QF-FS specimens.