Effect of maternal dioxin exposure on pituitary mRNAs in fetal rats at gestational day 18

We found that oral administration of TCDD (1 µg/kg) to pregnant rats on gestational day 15 suppressed pituitary syntheisis of growth hormone during the last fetal stage. We performed a DNA microarray analysis to identify the genes linked to the attenuated expression of GH, using the male and female fetal pituitary at GD18 when the reduced expression of GH started to occur because of TCDD. Total RNAs were extracted from the pituitaries of the control and TCDD-exposed fetal rats at gestational day 18 (both males and females, each N=3), and their cDNAs were applied to the analysis using 44K 60-mer oligomicroarray (Whole Rat Genome Microarray 4x44K v3; Agilent Technologies)

本研究发现，于妊娠第15天对妊娠大鼠经口给予2,3,7,8-四氯二苯并对二恶英（TCDD，1 µg/kg），可在胎儿发育晚期抑制其垂体生长激素（growth hormone）的合成。为鉴定与生长激素表达减弱相关的基因，本研究选取妊娠第18天（GD18）的雌雄胎鼠垂体开展DNA微阵列分析（DNA microarray analysis）——该时间点正是TCDD诱导生长激素表达降低开始出现的时期。实验过程中，我们从对照组与TCDD暴露组的妊娠第18天胎鼠垂体中提取总RNA，每组雌雄个体各3例（N=3），随后将提取的互补DNA（cDNA）应用于44K 60聚体寡核苷酸微阵列（全大鼠基因组微阵列4x44K v3；安捷伦科技（Agilent Technologies））的检测分析。