Objective: To investigate regulating effect of Yishen Gukang prescription on protein expression of glial fibillary acidic protein(GFAP)

c-fos and P substances in dorsal horn of spinal cord in a rat model of osseous metastasis tumor pain. Method: On the basis of osteolytic osseous metastasis model of adenocarcinoma of lung in nude mice

immunohistochemical staining method was adopted to observe expression of GFAP

c-fos and P substances in dorsal horn of spinal cord in a rat model in each group.Image analysis was conducted by image analysis software MIA4.0

five visual fields were chosen from each section to count optical density value of the positive substances expressed in each high magnification visual field under 400 microscope magnification. Result: 100% osseous metastasis occurred in nude mice of the model group

immunohistochemistry data indicated that GFAP

c-fos and P substances in dorsal horn of spinal cord in the model group were over expressed;no osseous metastasis occurred in nude mice of the group with lower dosage of Yishen Gukang prescription and the Chinese drug plus western drug group

immunohistochemistry data indicated that protein expression of GFAP

c-fos and P substances was at a lower level;osseous metastasis occurred in nude mice of the groups with moderate and higher dosage of Yishen Gukang prescription

but proteins expression in relation to pain such as GFAP

c-fos and P substances in dorsal horn of spinal cord in nude mice of these two groups were obviously lower than that of the model group. Conclusion: Yishen Gukang prescription has a certain abirritation by inhibiting protein expression of GFAP

c-fos and P substances in dorsal horn of spinal cord in nude mice.