抄録
The chemical modification of human recombinant interleukin-6(IL-6) with polyethylene glycol (PEG) was conducted to increase its thrombopoietic activity. PEG-modified IL-6(PEG-IL-6) was separated into several molecular weight fractions and characterized individualy. The specific activity of PEG-IL-6 was reduced with increase in its degree of PEG-modification, that is, whole molecular weight. On the other hand, the in vivo thrombopoietic activity of PEG-IL-6 was markedly increased. Especialy, PEG-IL-6, in which 54% of the 14 lysine amino groups of IL-6 were coupled with PEG, showed 10 times greater thrombopoietic effect than native IL-6. By the pharmacokinetic analysis, PEG-IL-6 greately enlarged the area under the time concentration curve. These findings suggesed that PEG-IL-6 may be a useful agent for the treatment of thrombocytopenia after chemotherapy.
