Rosen O, Suarez C, Schuster V L, Brion L P
Department of Pediatrics, Division of Neonatology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York 10461, USA.
Am J Physiol Regul Integr Comp Physiol. 2001 Feb;280(2):R365-75. doi: 10.1152/ajpregu.2001.280.2.R365.
Carbonic anhydrase (CA) facilitates acid-base transport in several tissues. Acidosis upregulates membrane-bound SDS-resistant hydratase activity in various tissues and CA IV mRNA in rabbit kidney. This study was designed to assess whether the expression of membrane-bound CA IV isozyme in mouse placenta is regulated developmentally and by maternal ammonium chloride loading at the end of pregnancy. For this purpose we used Northern blot analysis, Western blots of microsomal membranes, and immunocytochemistry. The expression of CA IV mRNA on Northern blots tripled from day 11 to day 15 and then remained stable until the end of pregnancy. Expression of CA IV immunoreactive protein on Western blot tripled from day 11 to day 15 and decreased almost to baseline by day 19. Strong staining for CA IV was detected by immunocytochemistry in labyrinthine trophoblast, in the endodermal layer of the yolk sac (both intra- and extraplacental) and in the uterine epithelium. Weak staining was observed in most fetal endothelial cells at 11 days but not later in gestation. Maternal acidosis did not upregulate the expression of CA IV mRNA or CA IV immunoreactive protein. Thus CA IV expression in mouse placenta is developmentally regulated. Maternal acidosis during the last quarter of pregnancy does not upregulate CA IV mRNA or CA IV immunoreactive protein.
碳酸酐酶（CA）在多个组织中促进酸碱转运。酸中毒会上调各种组织中膜结合的耐十二烷基硫酸钠水合酶活性以及兔肾中的CA IV mRNA。本研究旨在评估小鼠胎盘膜结合CA IV同工酶的表达是否受发育调控以及妊娠末期母体氯化铵负荷的影响。为此，我们使用了Northern印迹分析、微粒体膜的蛋白质免疫印迹和免疫细胞化学方法。Northern印迹上CA IV mRNA的表达从第11天到第15天增加了两倍，然后一直保持稳定直至妊娠结束。蛋白质免疫印迹上CA IV免疫反应性蛋白的表达从第11天到第15天增加了两倍，并在第19天几乎降至基线水平。免疫细胞化学检测到在迷路滋养层、卵黄囊（胎盘内和胎盘外）的内胚层以及子宫上皮中CA IV有强烈染色。在第11天，大多数胎儿内皮细胞中有弱染色，但在妊娠后期未观察到。母体酸中毒并未上调CA IV mRNA或CA IV免疫反应性蛋白的表达。因此，小鼠胎盘中CA IV的表达受发育调控。妊娠最后一个季度的母体酸中毒不会上调CA IV mRNA或CA IV免疫反应性蛋白的表达。
