Dipeptides Glu-Trp and Lys-Asp and peptide mixtures of the 5th thymosine fraction, as well as thymaline, stimulate the immune response when applied subcutaneously during 5 days and intensify the activity of neutrophils and protect splenocytes from the toxic effect of benzene and aflatoxin B~ in vitro. Amino acids (Glu, Trp, Lys, Asp, and Arg) and amino acid mixtures (levamine-70, cerebrolysine, and aviamine) differently affect the indexes of specific and nonspecific resistance under the same conditions and at the same dose. Key Words: peptides; amino acids; immune response; phagocytosis; detoxicationChronic microbic and nonmicrobic intoxications are known to inhibit the factors of specific and nonspecific resistance, which promotes intercurrent infections [2,7]. For this reason the immunocorrection of such pathological states should include drugs with combined action of specific and nonspecific parameters of immune defense. Some peptides [3,9], amino acids, and their mixtures [1,4,8,9] are able to act upon certain chains of specific and nonspecific resistance, but the combination of these effects has not been studied.The aim of the present investigation was to examine the combined effects of some peptide and amino acid preparations on such indexes of specific and nonspecific resistance as the immune response, phagocytosis, and detoxication in vitro and in vivo.

Benzene or benzene-dissolved Bl-aflatoxin in low doses promotes an increase of the Thy-1 § cell count in the bone marrow of mice and an enhancement of the thymusdependent immune response. In vitro aflatoxin and benzene are unable to induce the expression of Thy-1-antigen in bone marrow T-precursors.

After 60 days of intoxication, low doses of aflatoxin B 1 decreased the total protein concentration, an indicator of phagocytosis completeness, and had no effect on the level of lysosomal cationic protehls. Benzene decreases both parameters, but does not affect the total protein content. The amino acid preparations cerebrolysin and aviamine and glutamic acid normalize the phagocytic activity of granulocytes decreased by benzene, but not by aflatoxin.