Effect of lysergic acid derivatives on the liver fluke Fasciola hepatica

Abstract

Lysergic acid diethylamide derivatives, and a number of indole compounds related to serotonin, have been tested on preparations from the liver fluke Fasciola hepatica attached to a force transducer, and the concentrations which stimulated 50 per cent of these preparations (ED 50) have been determined. These derivatives can be arranged in an ascending order according to their ED 50 as follows: d-lysergic acid diethylamide, d-lysergic acid pyrrolidide, d-lysergic acid dimethylamide, methyl- d-lysergic acid diethylamide, d-lysergic acid monoethylamide, d-lysergic acid morpholide, 1-methyl- d-lysergic acid butanolamide, bromo- d-lysergic acid diethylamide, and l-lysergic acid diethylamide. All these compounds except for bromo- d-lysergic acid diethylamide and l-lysergic acid diethylamide had a lower ED 50 than serotonin and its related derivatives. There is a good correlation between the stimulant potency of these agents on the liver fluke and the reported hallucinatory effects on man.