Abstract

1. Racemic nor-epinephrine is distinctly more pressor than racemic epinephrine.

2. Inhibitory (sympathin I-mimetic) actions of nor-epinephrine are increased by N-alkyl substitution.

3. The structure of the N-alkyl group is an important factor influencing inhibitory potency.

4. Inhibitory effects are not prominent with those hydroxytyramine derivatives that do not contain the alcoholic hydroxyl of nor-epinephrine.

5. The significance of these findings is discussed.