Perinatal rat lung catalase gene expression: influence of corticosteroid and hyperoxia.
Perinatal rat lung catalase gene expression: influence of corticosteroid and hyperoxia.
复制标题
围产期大鼠肺过氧化氢酶基因表达：皮质类固醇和高氧的影响。
DOI：
10.1152/ajplung.1991.260.6.l428
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Massaro,D
中科院分区：
文献类型：
--
作者：
Clerch,LB;Iqbal,J;Massaro,D
地塞米松加速妊娠后期大鼠肺过氧化氢酶活性升高；新生儿高氧可提高大鼠肺过氧化氢酶活性。我们研究了在这些情况下过氧化氢酶基因表达的调控。过氧化氢酶mRNA/mg DNA在妊娠第22天升高，随后降至成人肺。过氧化氢酶mRNA的转录率在妊娠第22天高于妊娠第19天，而过氧化氢酶mRNA的半衰期（约7 h）在妊娠第19天与妊娠第22天相同。在预产期前48和24 h（妊娠22天）给予地塞米松可增加第20天和第22天过氧化氢酶mRNA浓度，但未改变过氧化氢酶mRNA的稳定性。出生后早期高氧（大于95% O2, 72 h）升高过氧化氢酶mRNA/mg DNA，使其半衰期增加一倍，但不改变其转录率。我们认为妊娠后期过氧化氢酶活性的正常升高和产前地塞米松治疗期间过氧化氢酶活性的增加受基因转录水平的调节。相比之下，新生儿高氧期间过氧化氢酶活性的升高是通过过氧化氢酶mRNA稳定性的增加介导的。
Dexamethasone accelerates the late gestational rise in rat lung catalase activity; neonatal hyperoxia elevates rat lung catalase activity. We studied the regulation of catalase gene expression in these instances. Catalase mRNA/mg DNA increased to gestation day 22 and then fell to the concentration in adult lungs. The rate of transcription of catalase mRNA was higher on gestation day 22 than gestation day 19, whereas the half-life of catalase mRNA (approximately 7 h) was the same on both days. Dexamethasone given 48 and 24 h before expected birth (gestation 22 days) increased catalase mRNA concentration at days 20 and 22 without a change in catalase mRNA stability. Early postnatal hyperoxia (greater than 95% O2, 72 h) elevated catalase mRNA/mg DNA and doubled its half-life without changing its rate of transcription. We conclude the normal late gestational elevation of catalase activity and the increase of activity during prenatal dexamethasone treatment are regulated at the level of gene transcription. By contrast, the elevation of catalase activity during neonatal hyperoxia is mediated posttranscriptionally by increased catalase mRNA stability.