Abstract

1 . The cardiac inhibitory effects of metamethoxybenzyl homomyristicylamine, its N-methyl derivative, and of 2-(metamethoxybenzyl)-6, 7-methylenedioxy-8-methoxy- and 2-(metamethoxybenzyl)-6-methoxy-7, 8-methylenedioxy-1, 2, 3, 4-tetrahydroisoquinoline are similar to those of α-fagarine.

2. In the lower dosage range used, the first of these compounds was comparable to α-fagarine in the intensity of its inhibitory effect, while the rest of the compounds appeared to be less active. At a higher dosage range all of the compounds and α-fagarine appeared to be equally inhibitory.

3. Studies on isolated ileum showed that α-fagarine, unlike quinidine or papaverine, exerted a depressant effect in lower dosages and a stimulant effect at higher dosages. This stimulant effect was not abolished by atropine. The synthetic compounds also showed the stimulant as well as depressant effects, though they were quantitatively different.

4. In antagonizing the actions of acetylcholine on the ileum, α-fagarine was quite inactive, while the synthetic compounds were about as active as papaverine. Against histamine, α-fagarine had only limited activity, while the synthetic compounds showed considerably more activity and were more active than either quinidine or papaverine.