THE CYTOLOGY OF THE ADRENAL MEDULLARY CELLS WITH SPECIAL REFERENCE TO THE STORAGE AND SECRETION OF THE SYMPATHOMIMETIC AMINES

Abstract

The adrenal medullary cells contain specific granular structures which fill the entire cytoplasm; the size of these granules varies between 0.1 and 0.6 [mu]. The sympathomimetic amines in the adrenal medulla are intra-cellularly localized within these specific granules. The catechols are rapidly liberated from the granules when the latter are subjected to a pH below 5, hypotonic solutions, freezing or drying. These specific catechol-containing structures are not secretory granules. During secretion by the adrenal medullary cells of the rat, epinephrine is liberated from the granules and probably rapidly transported through the cytoplasm and out of the cell. The adrenal medullary cells in the cow lack mitochondria of the conventional type. However, the catechol-containing granules are vitally stained with Janus green, and the succinic dehydrogenase of the cells is concentrated in the granules. This supports the view that these specific granules are comparable to mitochondria.