CONTRIBUTION TO THE CYTOSPECTROFLUOROMETRIC MEASUREMENT OF 5-HYDROXYTRYPTAMINE IN ENTEROCHROMAFFIN CELLS

Abstract

Cytofluorometry enables, under certain conditions, quantitative determination of the 5-hydroxytryptamine content of enterochromaffin cells. Preparations were obtained by: (1) fixation with 10% neutral formalin, (2) freeze-drying and exposure of the sections to formaldehyde released from aqueous formalin or paraformaldehyde and (3) Falck's method. For measurements the Leitz MPV microspectrophotometer and microspectrograph with a television oscilloscopic system were used. Absorption spectra, excitation spectra, emission spectra, photolysis and emission intensity recovery in cells were measured. The corrected data obtained included: absorption peak, 390 nm; excitation peak, 360 to 370 nm; and emission peak, 560 nm. Comparative observations were made on the fluorescence of the background.