Objective:To observe the effects of vitamin A deficiency during pregnancy on the lung vitamin A status

its receptor and pulmonary surfactant of fetal rats.Methods:Prenatal vitamin A normal(VAN)and marginal vitamin A deficiency(MVAD)of Sprague-Dawley rat models were employed.There were 6 in each group.Then they were randomly divided into dexamethasone(Dex)group and control group respectively.I.e VAN-Dex group

VAN-NS group

MVAD-Dex group and MVAD-NS group.From the gestational days 16 to 18

all the rats were given Dex or Saline by intramuscular injection respectively.On the gestational day 19

fetal rats were harvested by cesarean section.The vitamin A concentrations of lung were detected by high-performance liquid chromatography(HPLC)

and the levels of pulmonary surfactant(PS)and retinoic acid receptor(RAR)mRNAs were detected by semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR);then the values of PS and RAR mRNAs were compared to glyceraldehyde-3-phosphate dehydrogenase(GAPDH)mRNA.Results:(1)The vitamin A concentrations of lungs in VAN-NS group were higher than those of MVAD-NS group

higher in VAN-Dex group than in MVAD-Dex group

higher in MVAD-Dex group than in MVAD-NS group

and higher in VAN-Dex group than in VAN-NS group.There were significant differences among the four groups(P<0.05);(2)As to the levels of SP-B and SP-C mRNAs

they were higher in VAN-NS group than those in MVAD-NS group

and higher in MVAD-Dex group than in MVAD-NS group.There were significant differences between the two groups(P<0.05).The levels in VAN-Dex group were higher than those in VAN-NS group

higher in VAN-Dex group than in MVAD-Dex group

but there were no significant differences(P>0.05).(3)With regard to the levels of RAR mRNA

the levels of RAR-α and RAR-γ mRNAs in VAN-Dex group were higher than those in VAN-NS group

higher in MVAD-Dex group than in MVAD-NS group

lower in VAN-Dex group than in MVAD-Dex group

lower in VAN-NS group than in MVAD-NS group.The levels of RAR-β mRNA in the four groups were similar to those of the RAR-α and RAR-γ mRNAs.And There were significant differences(P<0.05).Conclusion:The vitamin A concentrations of lungs and the levels of SP-B and SP-C mRNAs

the levels of RAR mRNA

were all influenced by vitamin A deficiency during pregnancy.The fetal lungs of the MVAD’s mother is immature

but the effects of Dex will not be affected.