The influence of aromatic amino acid derivatives on the complement system under ionizing radiation

The activities of the complement classical, alternative, and lectin pathways are determined under conditions of X-ray irradiation in the blood of rats treated and not treated with synthetic Schiff base aromatic amino acid derivatives, nicotinyl-L-tyrosinate or nicotinyl-L-tryptophanate, before irradiation. In the case of the activities of the alternative and lectin pathways, no significant changes between irradiated animals and non-irradiated control animals are detected. However, the data obtained demonstrate significantly elevated activity of the classical complement cascade in the blood of irradiated animals (one day after irradiation), as compared to those not irradiated. This effect is less pronounced in rats treated with nicotinyl-L-tyrosinate or nicotinyl-L-tryptophanate one hour before irradiation. Based on the results obtained, we conclude that nicotinyl-L-tyrosinate and nicotinyl-L-tryptophanate are able to act as cytoprotectors.