Prenatal Dexamethasone On The Vitamin A Level Of Impact

PARTⅠTHE EFFECT OF ANTENATAL DEXAMETHASONE ADMINISTRATION ON THE SERUM VITAMIN A STATUS IN PRETERM INFANTSObjective:To observe the serum vitamin A status in preterm infants at day 1 after birth,and the effect of antenatal dexamethasone administration on the serum vitamin A status in the study subjects.Methods:According to if or not using dexamethasone from 24 hours to 7 days prior to delivery,thirty-seven preterm infants transported to our division of neonatology on the first day after birth were divided into two groups,one was the therapy group,the other was the control group.Then the serum concentrations of vitamin A and retinol-binding protein(RBP) of the total preterm infants were measured,and the difference of two groups were observed.Results:(1)Ten of the total study subjects(27.03%) were presented with subclinical vitamin A deficiency(SVAD),the others(72.97%) were presented with vitamin A deficiency(VAD).(2)Compared with the two groups,the serum concentrations of vitamin A and RBP in the therapy group were higher than those of the control group,there was a significant difference(P<0.05).Conclusion:(1)Preterm infants in this study were at high risk of vitamin A deficicency.(2)Antenatal dxamethasone administration can elevated the serum vitamin A status in preterm infants at day 1 after birth. PARTⅡTHE EFFECT OF ANTENATAL DEXAMETHASONE ADMINISTRATION ON THE TISSUE VITAMIN A STATUS IN FETAL RATSObjective : To study the effect of antenatal dexamethasone administration on the tissue vitamin A status in fetal rats.Methods:Twelve pregnant Sprague-Dawley(SD) rats were randomly divided into two groups,one was the Dex group,the other was the control group.From the gestational day 16 to 18,the rats of the two groups were given dexamethasone and saline by intramuscular injectionrespectively.On gestational day 19,fetal rats were obtained by cesarean section,then the vitamin A concentrations of tissues(lung,liver) were detected by high-performance liquid chromatography(HPLC).Results:(1)Compared with the two groups,the per unit vitamin A concentrations of lung and liver in Dex group were higher than those of the control group(P<0.05),exceptionally in lung(P<0.01).(2)The liver total vitamin A concentrations did not differ significantly between the two groups,but the lung total vitamin A concentrations were still higher than those of the control group(P<0.05).Conclusion:The antenatal dexamethasone administration can elevate the per unit lung and liver vitamin A concentrations,meanwhile elevate the lung total vitamin A concentrations,but not influence the liver total concentrations significantly.