Tyramin is a hydrochloric acid salt of parahydroxyphenylethylamin. The latter is the most active blood pressure raising constituent in watery extracts of ergot.1 It has been isolated from putrid meat2 and from other decomposing organic substances. Here it appears to be formed by the action of bacterial ferments on tyrosin, one of the common amino-acid building stones of the protein molecule. The structural relationship of tyramin to tyrosin and to the physiologically related epinephrin is shown in the following structural formula:
The action of tyramin on the circulation of animals was studied by Dale and Dixon,3 who found that the intravenous injection of 1 mg. into the cat or into other laboratory animals was followed by a sudden and marked rise of arterial blood pressure, reminiscent of that produced by epinephrin. As compared with the latter, however, the blood pressure changes showed a longer latent period, the