[Comparison of the effect of ambroxol and dexamethasone on the expression of pulmonary surfactant proteins in the fetal rat lungs].
OBJECTIVE
To investigate the effects of maternally administered dexamethasone and ambroxol on the mRNA levels of surfactant proteins (SP-A, SP-B and SP-C) expression in fetal rat lungs at gestational age day 19.


METHODS
A 19-day fetal rat lung model was employed. In situ hybridization was used to detect the expression of SP-B mRNA in alveolar type II cell, and the levels of SP-A, SP-B and SP-C mRNAs were detected by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).


RESULTS
(1) SP-B mRNA was detected in situ in alveolar type II cells in fetal rat lung of day 19 gestational age; (2) In the late developmental period of fetal rat lungs, alveolar type II cells were also found around bronchus; (3) Comparing to beta-actin mRNA, the relative values of SP-A, SP-B and SP-C mRNAs were 0.81 +/- 0.26, 0.97 +/- 0.20 and 0.88 +/- 0.11 in fetal lung in the control group. The relative values of mRNAs of SP-A, SP-B and SP-C to beta-actin were 1.04 +/- 0.16, 1.28 +/- 0.29, 1.09 +/- 0.25 in fetal lungs of the ambroxol injected rats, and were 1.08 +/- 0.25, 1.23 +/- 0.35, 1.21 +/- 0.25 in fetal lungs of the dexamethasone injected rats, respectively. Both ambroxol and dexamethasone-treated rats had significantly higher mRNA expression of surfactant proteins compared to the control saline injected animals (P < 0.05). (4) There were no significant differences between ambroxol and dexamethasone in the effects of increasing expressions of surfactant protein mRNAs (P > 0.05).


CONCLUSIONS
Antepartum administration of both ambroxol and dexamethasone can significantly increase fetal lung SP-A, SP-B and SP-C mRNAs expression.
Fu
Xue-ming
XM
Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing 400014, China.
Yu
Jia-lin
JL
Liu
Guan-xin
GX
Deng
Bing
B
D000551:Ambroxol / Q000494:pharmacology*; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology*; D005100:Expectorants / Q000494:pharmacology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology; D008168:Lung / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D011247:Pregnancy; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics; D037701:Pulmonary Surfactant-Associated Protein B / Q000235:genetics; D037721:Pulmonary Surfactant-Associated Protein C / Q000235:genetics; D037661:Pulmonary Surfactant-Associated Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
D005100:Expectorants; D005938:Glucocorticoids; D037662:Pulmonary Surfactant-Associated Protein A; D037701:Pulmonary Surfactant-Associated Protein B; D037721:Pulmonary Surfactant-Associated Protein C; D037661:Pulmonary Surfactant-Associated Proteins; D012333:RNA, Messenger; D000551:Ambroxol; D003907:Dexamethasone