The Middle Asian tortoise Testudo horsfieldii is one of the most radioresistant animals, with Lethal Dose (LD) 50/30 around 500 Gy. Extracts were prepared from different organs of the tortoise, and their biological activity was evaluated. Crude extract from the spleen was found to significantly increase survival of mice treated with lethal doses of radiation. In an iterative process, the active extract was purified by chromatography, and the fractions were screened for biological activity. Various vital parameters were monitored: peripheral blood leukocytes, spleen colonies, mitosis in the bone marrow, and survival after 30 days. The process concluded with the isolation, characterization, and synthesis of the tetrapeptide FTGN, which accelerated repopulation of the irradiated bone marrow at very low concentrations both in vivo and ex vivo.

中文翻译：

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一种来自陆龟陆龟脾脏的肽，可作为减少急性放射综合症的潜在助手。

中亚陆龟陆龟horsfieldii是最耐辐射的动物之一，致死剂量（LD）为50/30，约为500 Gy。从乌龟的不同器官中制备提取物，并评估其生物学活性。发现从脾脏中提取的粗品可显着提高用致死剂量放射治疗的小鼠的存活率。在迭代过程中，通过色谱法纯化活性提取物，并筛选级分的生物活性。监测各种重要参数：外周血白细胞，脾脏集落，骨髓中的有丝分裂以及30天后的存活率。该过程以四肽FTGN的分离，表征和合成作为结束，该四肽FTGN在体内和离体时都以非常低的浓度促进了辐照骨髓的重新繁殖。