Observations on the in vitro synthesis of adrenaline under physiological conditions

Publisher Website
Google Scholar
Abstract
Various tyrosine derivatives dissolved in oxygenated Ringer-glucose soln. at pH 6. 5 were submitted to the action of surviving tissue slices of bullock adrenal medulla. After 2 hr. the solns. were assayed colorimetrically to determine the increase in adrenaline content. Phenylethylamine was the most active compound, up to 40% being converted into an adrenaline-like chromogen. Tyramine and phenylalanine were about 1/4 as active while tyrosine, methyltyrosine, and hordenine were inactive[long dash]also dopa and methyldopa (assayed physiologically). A marked response was given by the unidentified catechol compound present in adrenal extracts, indicating that this may be an intermediate in the in vivo process. In the autolysis of both medulla and cortex tissue, with or without added tyramine, there was no evidence of any adrenaline synthesis. Phenylethylamine is tentatively regarded as the precursor of adrenaline in the bullock adrenal.