Nitric oxide
synthase gene expression in hyperoxia-induced lung injury in premature rat
Xu Feng 1, Fok Tai Fai 2, Yung
Edmund 2, Yang M 2, Jane Yin 2
1 Children's
Hospital, Chongqing University of Medical Sciences
2 Department of
Paediatrics £¬The Chinese
University of Hong Kong
Objective: To
studied the effect of hyperoxia on endothelial nitric oxide synthase (eNOS)
and inducible nitric oxide synthase (iNOS) gene expression in
hyperoxia-induced lung injury in premature rat.
Methods: Rat
litters were delivered prematurely at 21-day gestation and continuous
exposure to oxygen (>95%) or room air during 7 days. Their lungs were
examined for immunohistochemical staining of eNOS, iNOS. The levels mRNAs
of the eNOS,iNOS were measured by reverse-transcription polymerase chain
reaction (RT-PCR). eNOS and iNOS protein expression measured by Western
blotting.
Results: Hyperoxia
group developed severe lung damage. Compared to the room-air controls,
there was evidence of upregulation of NOS gene expression, including
elevated eNOS mRNA expression, increased eNOS and iNOS protein expression.
Immunohistochemical staining for eNOS and iNOS was strongly positive in the
hyperoxia group.
Conclusions: Hyperoxic
exposure of preterm rat pups causes upregulation of NOS gene expression,
which persists even in established oxygen-induced lung damage.