Objective:To explore the effects of anti-radiation pneumonia decoction (ARPD) on immune function in the rats with radiation-induced pulmonary injury. Method: SD rats were randomly divided into four groups: normal control group (group A)

model group (group B)

dexamethasone treatment group (group C) and ARPD treatment group (group D). Rats in group B

C and D were exposed to 6 MV X-ray at a dose of 20 Gy thoracically. After X-ray exposure group C and D were treated with dexamethasone (1.5 ×10-3 g·kg-1·d-1) and ARPD (35 g·kg-1·d-1) respectively by gastrogavage one time a day. The rats in group A and B were gavaged with equal volume 0.9% sodium chloride. The rats were sacrificed at days 7

15

30

50 after X-ray exposure. Pathological changes in spleen tissues were observed and the index numbers of thymus and spleen

T-cell subgroups of peripheral blood

serum hemolysin level

phagocytotic rates of macrophage in abdominal cavity were detected respectively. Result: The pathological changes in group D were slighter and recovered sooner than those in other groups exposed to X-ray. After 50 days

the thymus and spleen indexes

CD3+

CD4+

CD8+

hemolysin levels

phagocytotic rates of macrophage in group D were higher than that in group B and C (P<0.05). Conclusion: ARPD can improve the immune function in the rats with radiation-induced pulmonary injury.