Abstract OBJECTIVE: To study the role of antenatal glucocorticoid (dexamethasone and betamethasone) on bone morphogenetic protein (BMP) signal transduction of the rat fetal lungs. METHODS: Fifteen pregnant rats were randomly divided into five groups: the rats treated with dexamethasone for 1 day (1D-DEX) or 3 days (3D-DEX), with betamethasone for 1 day (1D-BEX) or 3 days (3D-BEX) or with normal saline (control group), followed cesarean section on the 19th day of gestation. The mRNA levels of BMP4, BMPR-II, Smad1 and ATF-2 of fetal rat lungs were ascertained by reverse transcriptase polymerase chain reaction (RT-PCR). The expression of BMP4, BMPR-II, Smad1 and ATF-2 antigen expression in fetal lungs was assessed by immune histochemical staining. The expression of BMP4 and BMPR-II was determined by Western blot. RESULTS: The levels of BMP4, BMPR-II and Smad1 mRNA expression were up-regulated in the 1D-BEX, 3D-BEX and 3D-DEX groups compared with those in the control group (P＜0.05). The immune histochemiscal analysis showed that the expression of BMP4, BMPR-II, Phospho-Smad1 (pSmad1) and ATF-2 in the 1D-BEX, 3D-BEX and 3D-DEX groups was significantly higher than that in the control group (P＜0.01). The results of Western blot demonstrated that the expression of BMP4 and BMPR-II protein increased significantly in the 1D-BEX, 3D-BEX and 3D-DEX groups when compared with the control group (P＜0.01). CONCLUSIONS: Betamethasone and dexamethasone may play important roles in the regulation of BMP signal transduction in the rat fetal lungs. Up-regulation of BMP4, BMPR-II and Smad1 might be one of crucial factors for the glucocorticoid-induced maturity of fetal lungs.［Chin J Contemp Pediatr, 2010, 12 (11):891-896］
CHEN Xiao-Qing,WU Sheng-Hua,ZHOU Xiao-Yu. Effects of antenatal administration of dexamethasone and betamethasone on signal transduction of bone morphogenetic protein in the fetal lungs of rats[J]. 中国当代儿科杂志, 2010, 12(11): 891-896.
CHEN Xiao-Qing,WU Sheng-Hua,ZHOU Xiao-Yu. Effects of antenatal administration of dexamethasone and betamethasone on signal transduction of bone morphogenetic protein in the fetal lungs of rats[J]. CJCP, 2010, 12(11): 891-896.
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