Effects of Psychotomimetic Compounds on Human Pseudocholinesterase

Abstract

The effects of serotonin, lysergic acid diethylamide (LSD), chlorpromazine, and reserpine on serum cholinesterase were determined manometrically. Inhibitions of 50% were obtained with 2 x 10⁻³ m serotonin, 10⁻⁶ m LSD, and 5 x 10⁻⁵ m chlorpromazine. Reserpine had no measurable effect. Marked potentiation of enzyme activity was achieved with extremely low concentrations of the three drugs (30% potentiation with 5 x 10⁻⁶ m serotonin, 50% potentiation with 6 x 10⁻⁹ m LSD, and 25% potentiation with 5 x 10⁻⁷ m chlorpromazine). This potentiation above control values may be of significance in explaining some central effects of these psychotomimetic agents. It is also felt that both potentiation and inhibition may be related to tertiary amine groupings on the inhibitor molecule. Submitted on February 20, 1957