A TECHNIQUE FOR LIGHT AND ELECTRON MICROSCOPIC IDENTIFICATION OF ADRENALIN- AND NORADRENALIN-STORING CELLS

Fixation of adrenal glands with 6.5% glutaraldehyde in Millonig buffer at pH 7.2 for 1 or more hours results in a yellow color in noradrenalin-storing cells while adrenalin-containing cells remains uncolored. When frozen sections of adrenal gland fixed in glutaraldehyde are treated with an ammoniacal silver solution, silver is reduced by noradrenalin cells in less than 30 seconds. A deep brown or black color according to the silver solution used, appears in noradrenalin-containing cells while the adrenalin ones remain uncolored. Based on these facts a technique for light and electron microscopic localization of noradrenalin has been developed. The results permit the following interpretation of the glutaraldehyde silver reaction for noradrenalin-containing cells. The condensation of glutaraldehyde with noradrenalin forms a yellow azomethine. Whereas this compound is insoluble adrenalin will not combine with glutaraldehyde and remains soluble. During washing adrenalin therefore disappears from sections while the yellow glutaraldehyde-noradrenalin compound remains. The aldehyde group of this compound reduces ammoniacal silver solutions.