Some observations on the oxidation of tyramine in the liver.

THE oxidation of tyramine in the liver has been investigated in vivo by Ewins & Laidlaw [1910] and in vitro by Hare [1928] and Bernheim [1931]. The former workers found that in feeding and liver perfusion experiments tyramine disappeared and p-hydroxyphenylacetic acid could be recovered from the urine and perfusates. Hare and Bernheim, using the Barcroft and Warburg manometric techniques, studied the oxidation of tyramine by liver extracts and " suspensions ". In the course of recent work I have made further observations which seemed to be of interest concerning the oxidation of tyramine and the general question of the investigation of tissue oxidations.