EFFECT OF THE PEPTIDE OF THYMIC ORIGIN (SYNTHETIC THYMOHEXINE-RKNVYR)ON HEMATOPOIETIC-CELL PROGENITORS IN INTACT AND IRRADIATED ANIMALS

Thymohexine treatment of intact CFU-S was shown not to change their ca pacity to form colonies both in vivo and in vitro. Thymohexine, simila rly to thymus cells, increased colony yield from rabbit antimouse brai n antiserum (RAMBS)-treated bone marrow. Combined treatment with thymo hexine and thymocytes did not restore colony formation by RAMB serum-t reated bone marrow. Thymohexine halved the harmful effect of low doses of ionizing radiation on CFU-S, and, moreover, treatment with the pep tide after 4 Gy-irradiation led to more intensive restoration of CFU-S population as compared to control.