A STUDY OF THE POTENTIATION OF TRYPTAMINE BY MONOAMINE OXIDASE INHIBITORS IN THE DOG

¹ Biomedical Research Department, Pitman-Moore Division of The Dow Chemical Company, Indianapolis, Indiana

Monoamine oxidase inhibitors (-phenylisopropylhydrazine, harmine, or pivalylbenzhydrazine) were shown to enhance the action of tryptamine on systemic blood pressure by a combination of two mechanisms: 1) an increase in the blood levels of circulating tryptamine following its injection, 2) a peripheral enhancement shown in the perfused leg.

The peripheral enhancement in the perfused leg was also found for tyramine but not for dopamine. Although the systemic response to tyramine, dopamine and tryptamine was enhanced by the monoamine oxidase inhibitors the enhancement of the response to dopamine was not observed as regularly as was the enhancement of response to tyramine and tryptamine.