THE CENTRAL STIMULANT ACTION OF SOME VASOPRESSOR AMINES

¹ Pharmacology Department, Research Laboratories, The Wm. S. Merrell Company, Cincinnati, Ohio

The subcutaneous administration of seven commercial vasopressor amines in doses equal to fractional parts of the LD₅₀ as determined at 26°C. showed that Benzedrine, Ephedrine, and Propadrine caused the greatest central stimulant action as measured by the total activity of white rats.

Maximal stimulating effects observed for these three compounds were obtained with five, ten, and twenty per cent of the LD₅₀ of Ephedrine; ten and twenty per cent of the LD₅₀ of Propadrine; and twenty per cent of the LD₅₀ of Benzedrine.

Vonedrine caused a small amount of stimulation in the higher doses while Tuamine, Privine, and Neo-Synephrine had no significant effect in the doses employed.

Twenty per cent of the LD₅₀ seems to be the most suitable dosage level for preliminary screening tests since this dose alone produced maximal observed effects with all compounds.