RESUMO
Effect of carboxylic acids - structurally related to amino acids, on the proliferation activity of the cells in organotypic cultures of rat spleen was first studied. It was found that almost all aliphatic carboxylic acids have stimulating effects on proliferative activity of cells in young and old rats. In contrast only 3 from 14 active amino acids in young rats were able stimulate proliferation, but 11 amino acids inhibited it. In the old rats a number of the active amino acids was decreased until 4, an inhibiting effect was observed in 3 of them. Thus, the carboxylic acids are able to stimulate the regeneration processes in the immune tissue both in the young and old organisms. This fact can be a base for the research of new medical substances for the stimulation of the immunogenesis by the aging.