Comparative studies on the influence of radioprotectors and amino acids on the chromosome-damaging activity of 8-hydroxyquinoline sulfate in human lymphocytes in vitro

The influence of the radioprotectors cystaamine and aminoethylisothiouronium (AET) as well as the amino acids l-cysteine, l-alanine, l-arginine, l-asparagine, l-glutamic acid, l-histidine and l-methionine on the cytogenetic action of 8-hydroxyquinoline sulphate (8-HCHS) was tested in human lymphocyte cultures in vitro. An excess of l-cysteine, cysteamine, and l-asparagine, when added to the cultures simulataneously with 8-HCHS, distinctly reduced the chromosome-damaging effect of this agent. l-Glutamic acid and AET exerted a protective activity to a lesser extent. l-Methionine only displayed some effect in reducing the relatively rare isochromatid aberrations induced by 8-HCHS. The other amino acids had no effect on the chromosome-damaging action of this substance.The dose dependence of the protective activity as well as the degree of effectivity and the spectrum of action of the different protectors are compared. The possible mechanisms of action are discussed.