Therapeutic effect of rhIL-11 administered at different times on acute radiation sickness in rhesus monkeys

Objective: The author describes the therapeutic effect of recombinant human interleukin-11 (rhIL-11) administered at different times on acute radiation sickness in monkeys. Methods: Rhesus monkeys irradiated with 3.0 Gy 60Co γ rays were divided into 3 groups. One group was the control administered with vehicle, the second one was subjected to administer rhIL-11 on days 0-13 after TBI (60 μg·kg-1·d-1, sc) and the third one to administer rhIL-11 on days 13-26 after TBI at the same doses. Results: The early treated group had higher platelet nadirs compared with that of the other two. The duration of platelet and leukocyte numbers below 50% of their baseline values shortened significantly in animals treated with rhIL-11, especially in the early treated group. During the first week after irradiation, the early treated group had lower erythrocyte count compared with the control, but it began to rise at day 19 after irradiation. Semi-solid bone marrow cell culture demonstrated that rhIL-11 could stimulate bone marrow cells to form more CFU-MK, CFU-Mix, CFU-E, BFU-E and CFU-GM in vitro. The authors also got the same results in histopathological observation. Conclusion: rhIL-11 administered at different times can not only accelerate the haematopoietic recovery of acute radiation sickness in rhesus monkeys, but also result in better therapeutic effect when administered earlier