Abstract
The results obtained with the method of Shaw (1938) for the assay of "adrenaline" in blood and tissues (adrenal glands, liver, spleen, kidney, brain, heart) are due to the presence in these tissues not only of adrenaline itself, but also of adrenaline-like substances which contain a catechol nucleus, and of ascorbic acid. Thus, although the method is not specific for adrenaline, it can be used for investigations of adrenal and adrenergic function in a broader sense. It is no longer held that the low denominator of the "specific ratio" obtained by Shaw''s method for many tissues is due to the presence of adrenaline in combination with cortical hormones.