SOME PHARMACOLOGICAL EFFECTS OF A SERIES OF TRYPTAMINE DERIVATIVES.

The methods of synthesis and some pharmacological properties of a number of N-substituted tryptamines are described. Peripheral vasopressor activity decreased with increase in complexity of the substituent and was not related to toxicity or to behavioural activity. Activity in increasing the rectal temperature of rabbits appeared to parallel modifications in the open-field behaviour of rats. Some compounds were investigated for their ability to block a conditioned avoidance-response in rats and to affect operant conditioning in cats. Evidence is presented which suggests that the tryptamine derivatives are metabolized in vivo to more active forms.