Action of 5-hydroxytryptamine on growth of Raphanus sativus root

Abstract

5-hydroxytryptamine has an intense inhibitory action on the growth of Raph. sativus root for then days following germination in a tenthousandth molar concentration.

This inhibitory effect is even more manifest in a concentration of a hundredthousandth molar, but can scarcely be appreciated at a millionth molar concentration.

The inhibitory action of 5-hydroxytryptamine is practically that of 3-propionie indol in the same concentrations.