COMPARISON OF THE PRESSOR EFFECTS OF SOME NEW ALKYL DERIVATIVES OF -PHENYLETHYLAMINE

¹ From the Department of Pharmacology and Toxicology, Yale University, New Haven, Connecticut

1. The pressor activities of -phenylethylamine and eight of its newly synthesized methyl and ethyl derivatives are compared on cats and dogs.

2. None of the derivatives is more active than the parent substance.

3. A methyl group in the para position does not appreciably alter intensity of action although it shortens duration slightly.

4. An ethyl group in the para position moderately decreases both intensity and duration of action.

5. In the group of compounds with methyl substitution on the nitrogen, a second methyl group in either the para or meta position gives a substance slightly less active than phenylethylamine both in duration and intensity. When the second methyl group is substituted in the ortho position, pressor activity is reduced greatly. An ethyl group in the para position is associated with a weak and uncertain pressor action and often a strong tendency to lower blood pressure.

6. The two ethylamine derivatives are depressor regardless of whether a methyl group is substituted in the para or meta position.

7. Both N-ethyl derivatives and also the para-ethyl N-methyl compound cause a reversal of the pressor response normally produced by the other compounds in the series.