Abstract
The frog adrenals have been considered to contain only one type of chromaffin cells which stores both noradrenaline and adrenaline. Application of lead hematoxylin staining to the glutaraldehyde or formalin fixed adrenals of the frogs, Rana catesbiana and R nigromaculate, revealed specifically and cleary the adrenaline storing cells. They are mainly found in the peripheral region of the adrenal tissues. They have several slender finger-like processes connected with each other to form a network throughout the adrenal tissues. Argentaffin, iodate reaction positive, noradrenaline storing cells were found to be situated in small clumps in the central area of the adrenals.
Also in the adrenals of the toad, turtle, hen, rat, mouse, guinea pig, rabbit and hamster, the combined argentaffin reaction and lead hematoxylin staining after the glutaraldehyde and formalin fixation afforded clear differentiation of the two types of chromaffin cells.
Closer association of A-cells with the adrenal cortical cells than NA-cells was confirmed in the adrenals of several lower vertebrate species.
Injection of reserpine in mice, guinea pigs and bullfrogs caused degranulation both in the adrenaline and noradenaline storing cells, whereas insulin administration affected only the former type cells.
