[en] Objective: To observe the effect of recombinant human interteukin-11 (rhlL-11) on expressions of interteukin-11 receptor a-chain (IL-11Rα) and glyeoprotein 130 (gpl30), an additional signal transducer, in IEC-6 cells after neutron irradiation. Methods: IEC-6 cells were exposed to 4.0 Gy neutron and administered with 100 ng/ml rhIL-11 12 h before or immediately after irradiation. The apoptosis and necrosis rates and expressions of IL-11Rα and gpl30 were detected by flow cytometry, immunohistochemistry, Western blot, and image analysis. Results: The apoptosis rate of IEC-6 cells was increased by irradiation at 6 h (P<0.01), IL-11 stimulation resulted in a decreased apoptosis rate in irradiated IEC-6 cells (P<0.05). In normal control IEC-6 cells, IL-11Rα was strongly expressed in the cellular membrane and cytoplasm. The level of IL-11Rα expression significantly decreased at 6 h after irradiation (P<0.01) and returned to the normal level at 24 h after the irradiation. In IEC-6 cells treated with both radiation and rhIL-11, the level of IL-11Rα expression was higher than that of the irradiated cells (P<0.05), while gpl30 protein was strongly expressed in the cytoplasm of IEC-6 cells. After irradiation, we found a progressive decrease in the expression of gpl30 protein (P<0.05) in 48 h, while in rhIL-11-stimulated cells, it returned to the normal level at 24 h after irradiation and decreased at 48 h, but still higher than that of the irradiated-only cells (P<0.05). Conclusions: rhIL-11 can protect IEC-6 cells from neutron irradiation damage. The protection effect of rhIL-11 might be connected with its ability of up-regulating expressions of specific ligand-binding subunit IL-11Rα and signal-transducing subunit gpl30. (authors)