Novel Peptide Isolated From Middle Asian Tortoise Spleen Extract Induces Repopulation of Mice Bone Marrow After Irradiation

The Middle Asian tortoise (Testudo horsfieldii) is one of the highest radio resistant animals (LD 50/30 – 500Gy). The extract derived from tortoise spleen significantly increases survival of mice treated with lethal doses of γ-irradiation[1-5]. The crude tortoise spleen extract was treated by various purification methods leading to the isolation and identification of a tetrapeptide with a high biological activity. A synthetic analogue of the natural peptide preserves the biological activity. Here in we show that the tetrapeptide activates the early hematopoietic progenitor cells, thereby accelerating repopulation of the irradiated bone marrow with a concomitant beneficial effect on mice survival after irradiation. The results obtained here open the gate towards improved bone marrow transplantation.1. Turdiev, A. A., Usmanov, R. B., Madzhidova, D. Kh. and Nigmatov, Z. (1985) Radiobiology, 25, 655-659.2. Turdiev, A. A., Prus, E. K., Brain, A. P. R. and Quinn, P.J. (1990) Tissue Cell, 22, 385-387.3. Turdiev A.A., Usmanov R., Alexandrov V.V., Philutovich O.S. (1998) Radiation Biology and Radioecology, vol.38, 2, 63-70.4. Turdiev A.A. et al. (2000) Blood, vol.96, 11, nov.16, p.156-1575. Turdiev A.A., Agent Derived from Tortoise Spleen Stimulating Mammalian Hemopoiesis . Patent # 157772, 04-09-2003, Israel.