EFFECT OF PH TEMPERATURE OSMOLARITY AND DRUGS ON 5-HYDROXYTRYPTAMINE CONTENT AND LIGHT AND ELECTRON MICROSCOPIC STRUCTURE OF RAT MAST CELLS IN VITRO

The effect of pH, temperature, osmolarity and of some drugs, commonly used in amine uptake and release experiments, on the 5-HT content of rat peritoneal mast cells was studied in vitro. The results were compared with morphological alterations of mast cells at light and electron microscopic level. The release of 5-HT increased, with the rise of temperature and hypotonicity of the incubation medium and with that of the incubation time. A pronounced release of 5-HT was found at pH below 4.0. The 5-HT release correlated well with degranulation and degenerative morphological changes of mast cells. The amine release induced by imipramine, chlorpromazine and Segontine® was dose-dependent. It was interpreted as a secondary phenomenon due to the destruction of the cells with drugs with subsequent leaking out of 5-HT. At room temperature reserpine caused only a slight release of 5-HT, but observed morphological changes were interpreted as a cause of a specific 5-HT release. © 1969.