ABSTRACT
Thymohexine treatment of intact CFU-S was shown not to change their capacity to form colonies both in vivo and in vitro. Thymohexine, similarly to thymus cells, increased colony yield from rabbit antimouse brain antiserum (RAMBS)-treated bone marrow. Combined treatment with thymohexine and thymocytes did not restore colony formation by RAMB serum-treated bone marrow. Thymohexine halved the harmful effect of low doses of ionizing radiation on CFU-S, and, moreover, treatment with the peptide after 4 Gy-irradiation led to more intensive restoration of CFU-S population as compared to control.
Subject(s)
Adjuvants, Immunologic/pharmacology , Oligopeptides/pharmacology , Peptides/chemical synthesis , Peptides/pharmacology , Stem Cells/drug effects , Stem Cells/radiation effects , Thymus Gland/chemistry , Animals , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Peptides/analysis , Radiation ChimeraABSTRACT
The radiotherapeutic effect of thymogen (Glu-Trp) and thymohexin (Arg-Lys-Asp-Val-Tyr-Arg) synthetic peptide immunomodulators was investigated. Both thymogen and thymohexin were demonstrated to be able to reduce the damaging effect of ionizing radiation (1 Gy) on CFU-S by half. The treatment by these preparations after irradiation at dose of 4 Gy leads to more intensive restoration of CFU-S population as compared with control.
Subject(s)
Adjuvants, Immunologic/therapeutic use , Dipeptides , Hematopoietic Stem Cells/drug effects , Oligopeptides/therapeutic use , Peptides/therapeutic use , Radiation Injuries, Experimental/prevention & control , Radiation-Protective Agents/therapeutic use , Adjuvants, Immunologic/pharmacology , Amino Acid Sequence , Animals , Female , Hematopoietic Stem Cells/radiation effects , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Molecular Sequence Data , Oligopeptides/pharmacology , Peptides/pharmacology , Radiation Injuries, Experimental/etiology , Radiation-Protective Agents/pharmacologyABSTRACT
The data concerning the reasons of CFU-S radioresistance increase after low dose irradiation of mice were obtained; the reparation processes in CFU-S adapted by low dose irradiation were shown to be more active than in intact ones. Colony formation increase was demonstrated to be more pronounced in adapted animals when they had been injected by 50 mcg of synthetic polyribonucleotide PolyI-PolyC two days before irradiation in challenge dose. The thymogen immunomodulator administration to adapted and intact donor animals leads to the increase of colony yield in equal extent.
Subject(s)
Adaptation, Physiological/radiation effects , Dipeptides , Hematopoietic Stem Cells/radiation effects , Radiation Injuries, Experimental/physiopathology , Adaptation, Physiological/drug effects , Adjuvants, Immunologic/pharmacology , Adjuvants, Immunologic/therapeutic use , Animals , Hematopoietic Stem Cells/drug effects , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Peptides/pharmacology , Peptides/therapeutic use , Poly I-C/pharmacology , Poly I-C/therapeutic use , Radiation Dosage , Radiation Injuries, Experimental/prevention & control , Radiation ToleranceABSTRACT
Whether accessory T cells can be replaced by the synthetic immunomodulators thymogen (Glu-Trp) and thymohexin (Arg-Lys-Asp-Val-Tyr-Arg) was studied. The latter immunomodulator was found to show a 3-fold increase in splenic colony formation after incubation of bone marrow cells with rabbit antimouse brain serum (RAMBS). The former preparation failed to show the same action. Its effect was close to that of thymocytes. When the recipients exposed to lethal irradiation were administered the RAMBS-treated bone marrow cells and one of the peptides, it was shown that in concomitant administration, thymohexin and thymocytes lost their ability to restore colony formation by RAMBS-treated bone marrow. Thymogen did not suppress the stimulating activity of thymocytes. It is suggested that the differences observed between the tested peptides in their ability to recover colony formation were determined by their structure.
