[Changes in the therapeutic spectrum with respect to the pharmacological and radioprotective activity after O-alkylation of serotonin and 5(2-hydroxyethoxytryptamine)].

In experiments with mongrel mice, a study was made of the pharmacological activity of serotonin and its O-alkyl derivatives. It was estimated by the two indices, that is, the radioprotective properties and the influence on a local blood channel in the spleen, the modifying effect of the agents' toxicity being estimated as well. As an O-alkyl group of 5-alkoxytryptamines was elongated from one to three carbon atoms and the toxicity of the substances increased, their radioprotective effect decreased more readily than their effect on the local blood channel. The shortening of the range of the therapeutic action of the agents under study, with regard to the two pharmacological indices mentioned above, the alkyl group being lengthened, followed a logarithmic function which was more pronounced in relation to the radioprotective index (cos alpha 1/cos alpha 2 = 1.58).