EFFECT OF rhIL-6 ON EARLY HEMATOPOIETIC RECOVERY IN IRRADIATED MICE

The effect of recombinant human interleukin-6 ( rhIL-6) on the early phase of post-irradiation hematopoietic recovery ( mainly CFU-S, CFU-GM and CFU-E) has been studies in 6.5 Gy gamma-irradiated C57BL / 6J mice, which had been given subcutaneous injection of rhIL-6 b. i. d. at 10, 100, 200, 500 and 1 000μg/kg/d for 4 or 6 consecutive days started from 30 min after irradiation. It was shown that the effect of IL-6 on the early phase of post-irradiation hematopoietic recovery is dose-dependent and diphasic. At the doses of 200-1000μ/kg/d, IL-6 had a favorable effect on post-irradiation hematopoietic recovery expressed as increse of spleen weight and CFU-S, and elevation of CFU-GM yield and total CFU-GM content in femur. Administration of relatively low doses of IL-6(10-100 μg/kg/d) suppressed postirradiation hematopoietic regeneration. High a dose (1 000μg/kg/d) did not show any stronger stimulative effect on post-irradiation hematopoietic reconstitution. There is an optimal range of IL-6 dose for

The effect of recombinant human interleukin-6 ( rhIL-6) on the early phase of post-irradiation hematopoietic recovery ( mainly CFU-S, CFU-GM and CFU-E) has been studies in 6.5 Gy gamma-irradiated C57BL / 6J mice, which had been given subcutaneous injection of rhIL-6 b. i. d. at 10, 100, 200, 500 and 1 000μg/kg/d for 4 or 6 consecutive days started from 30 min after irradiation. It was shown that the effect of IL-6 on the early phase of post-irradiation hematopoietic recovery is dose-dependent and diphasic. At the doses of 200-1000μ/kg/d, IL-6 had a favorable effect on post-irradiation hematopoietic recovery expressed as increse of spleen weight and CFU-S, and elevation of CFU-GM yield and total CFU-GM content in femur. Administration of relatively low doses of IL-6(10-100 μg/kg/d) suppressed postirradiation hematopoietic regeneration. High a dose (1 000μg/kg/d) did not show any stronger stimulative effect on post-irradiation hematopoietic reconstitution. There is an optimal range of IL-6 dose for treating the radiation-induced bone marrow failure, which lies near 500 μg / kg / d under the condition of our experiment. These findings are of practical value to the application of IL-6.