Objective    To investigate the effects and mechanism of nerve growth factor (NGF) on the airway inflammation of asthmatic mice.     Methods    Male SD rats (n=24) were randomly divided into the control group (group A)

the asthmatic group (group B)

the anti-NGF group (group C)

8 mice in each group. The total cell count and classified count of cells in the bronchoalveolar lavage fluid (BALF) were performed.The pathological changes of the lung tissues were detected by HE staining. The concentrations of IL-4

IFN-γ and NGF in BALF were measured by ELISA. The mRNA expression of IL-4

IFN-γ and NGF in the lung tissues were detected by RT-PCR.     Results    Compared with the group A

not only the number of the total cells and classified cells in BALF significantly increased (P0.05) in the group B

but also the mRNA and protein levels of IL-4 and NGF (P0.01)

but the mRNA and protein levels of IFN-γ significantly decreased (P0.01). Compared with the group B

the number of the total cells and classified cells in BALF significantly decreased (P0.05) in the group C

while the mRNA and protein levels of IL-4 and NGF significantly decreased (P0.01)

but the mRNA and protein levels of IFN-γ showed no significant difference. The NGF levels in BALF of the group B were positively correlated with the number of total cells

eosinophils and lymphocytes in BALF (r=0.833

0.944

0.949

P0.05)

the mRNA and protein levels of IL-4 in BALF (r=0.848

0.944 respectively

P0.01)

but not correlated with the mRNA and protein levels of IFN-γ in BALF(r=0.611

0.122 respectively

P0.05).     Conclusion    NGF may play a key role in the formation of airway inflammation in the asthmatic rats by promoting the secretion of Th2 cytokines.