Accumulation and release of acridine derivatives by intact platelets

A new approach to the investigation of accumulation of acridine derivatives and release by platelets is proposed. At high concentrations of acridine orange (AO) inside dense bodies, a two component fluorescence spectrum with maxima at 530 and 640 nm has been recorded. Computer deconvolution of spectra provided additional information on the mechanism of dye accumulation and release. AO release from PAF-stimulated human platelets was analysed in details. A 10 +/- 2.5-s delay in alteration of the shortwave component was observed. Changes in the longwave component were not preceded by a lag period. These data suggest a possibility of dye redistribution in the cell after stimulation.