ADRENALINE AND NORADRENALINE IN THE ADRENAL MEDULLA DURING POSTNATAL DEVELOPMENT OF THE RAT12

Abstract

THE adrenal glands of fetuses and newborn animals of many mammalian species have been reported to contain more noradrenaline in proportion to the total catechol amine content than adrenals of adult animals (10, 11, 13, and others). However, the content of these catechol amines has usually been expressed either in terms of percent of adrenal weight, or as micrograms per gland, without data on the medullary volume. Little is therefore known of age dependent differences in the medullary concentration of adrenaline and noradrenaline. Moreover, all previous studies on the development of the adrenal medulla have apparently been made without knowledge of the fact that there are two different types of adrenomedullary cells, of which one secretes adrenaline, the another noradrenaline (2, 3, 6, 7, 8, 9). The present report deals with observations made using both chemical and histochemical methods for the study of adrenaline and noradrenaline in the adrenal medulla of rats of varying ages.