Mizoguchi Y, Kim J Y, Sasaki T, Hama T, Sasaki M, Enami J, Sakai S
Department of Animal Breeding, Faculty of Agriculture, University of Tokyo, Japan.
Endocr J. 1996 Oct;43(5):537-44. doi: 10.1507/endocrj.43.537.
In order to examine the time-dependent expression of the PRL receptor (PRL-R) gene at lactogenesis, the level of PRL-R mRNA was determined following ovariectomy in pregnant mouse mammary gland. Following reverse transcription, the quantity of mRNA was measured by the competitive polymerase chain reaction. The casein (a 22,000 molecular weight component) mRNA level was measured as a marker for milk synthesis. Following ovariectomy, the onset of abortion occurred mostly at 22-23 h and the level of casein mRNA began to increase at 12 h. The long and short forms of PRL-R mRNAs were detected in a molar ratio of 1:0.2 on day 12 of pregnancy. Eight h after ovariectomy, the long form of PRL-R mRNA began to increase, showing a bell-shaped profile with the highest peak at 16 h. The short form of PRL-R mRNA was at low levels and remained constant. The levels of the long form of PRL-R mRNA decreased similarly in the presence and absence of foster pups from 24 to 48 h. Conversely, casein mRNA were maintained at high levels by supplying foster pups. The level of the long form of PRL-R mRNA reached a maximum prior to abortion. The present experiments demonstrated that the acute expression of the PRL-R gene occurred in the mammary gland at lactogenesis.
为了研究催乳素受体（PRL-R）基因在泌乳发生过程中的时间依赖性表达，在怀孕小鼠乳腺切除卵巢后测定PRL-R mRNA的水平。逆转录后，通过竞争性聚合酶链反应测量mRNA的量。测量酪蛋白（一种分子量为22,000的成分）mRNA水平作为乳汁合成的标志物。切除卵巢后，流产大多发生在22-23小时，酪蛋白mRNA水平在12小时开始增加。在怀孕第12天，检测到PRL-R mRNA的长、短形式，摩尔比为1:0.2。切除卵巢8小时后，PRL-R mRNA的长形式开始增加，呈钟形曲线，在16小时达到最高峰。PRL-R mRNA的短形式水平较低且保持恒定。在有和没有代乳幼崽的情况下，PRL-R mRNA长形式的水平在24至48小时内类似地下降。相反，通过提供代乳幼崽，酪蛋白mRNA维持在高水平。PRL-R mRNA长形式的水平在流产前达到最大值。本实验表明，PRL-R基因的急性表达发生在泌乳发生时的乳腺中。
