Abstract: Objective To investigate the changes in the expression of nuclear receptor subfamily1 (Nr1d1) in the lungs of rats
with ventilation-induced lung injury and explore the molecular mechanism. Methods Seventy-two rats were randomly
divided into 4 groups for observation at 4 time points (1:00 AM, 7:00 AM, 1:00 PM and 7:00 PM), and each group was further
divided into 3 subgroups (Group FB, Group LV and Group HV). After ventilation for 3 h, the rats were sacrificed and lung
tissue samples were obtained for testing the expression of Nr1d1 using gene chip technology and RT-PCR. Results Nr1d1 gene
expression was down-regulated in HV group as shown by gene chip RT-PCR data. Cosine analysis showed that Nr1d1
expression exhibited a rhythmicity in FB group (P<0.05). Conclusion The rhythmicity of Nr1d1 expression disappears as the
tidal volume the increase. Diminished Nr1d1 expression is closely correlated with ventilation-induced lung injury in rats.