Objective   To investigate the expression of Src-suppressed C kinase substrate (SSeCKS) in the neonatal rat lung after hyperoxia-induced injury.    Methods   Totally 64 rats at the age of 12 h were randomly and equally divided into 2 groups

control group (normal air condition) and hyperoxia-induced lung injury group (O

2

95% and CO

2

5%). Then the rats were executed at the time points of 12

24

48 and 72 h after hyperoxic exposure

and the right upper lung was resected for the examination of histopathology and immunohistochemistry

the right below lung for wet weight/dry weight ratio

and the left

lung for detecting the expression of SSeCKS by Western blot analysis. The location of SSeCKS in the cells of lung tissue was tested by confocal scanning microscopy.    Results   At 24 h after the hyperoxic exposure

HE staining showed a few red blood cells in the alveoli and thickening alveolar wall. There were more red blood cells

distended alveolar septa and granulocyte infiltration in 48 h. Obvious acute inflammation

including hemorrhage

large amount of red blood cells

inflammatory cell infiltration into alveolar wall appeared at 72 h.  In control group

SSeCKS was detected little. But in hyperoxia-induced lung injury group

the expression level of SSeCKS started to increase at 24 h

reached to the peak at 72 h and continued to increase with the elapse of time. SSeCKS was located in the capillary endothelial cells of alveolar septa.    Conclusion   SSeCKS is involved in the process of hyperoxia induced lung injury.