Effects of n-decylamine and toluidine blue on the electric capacitance of isolated rat mast cells.

The electric capacitance of isolated rat mast cells and its change under the influence of either n-decylamine or toluidine blue was investigated. Since the electric circuit employed in the detection unit is the one merely sensitive for the capacitance changes, output signals pertain to the capacitance of the tested cell alone. N-decylamine released histamine without accompanying degranulation; and it caused a marked swelling of mast cells and a striking decrease of capacitance, although electric capacitance is usually proportional to the size of the cell. Morphological changes induced by toluidine blue are seemingly correlated with the changes in capacitance. At the concentrations (25-50 microgram/ml) in which the mast cell became enlarged, electric capacitances exceeded the control value. However, at the concentrations higher than 100 microgram/ml in which the cell became shrunken, the capacitance values were less than control value. Pretreatment with DNP (0.1 mM) or oxyphenbutazone (0.05-0.2 mM) was of little effect in inhibiting the histamine release, morphological alterations and capacitance changes due to n-decylamine, but pretreatment with either prevented all of those changes produced by toluidine blue. The mechanism of the capacitance changes in mast cells induced under influence of those compounds is discussed.