Monfared Ali Louei
Division of Anatomy and Histology, Department of Basic Sciences, Faculty of Para-Veterinary Medicine, University of Ilam, Ilam, Iran.
Toxicol Ind Health. 2014 Mar;30(2):174-81. doi: 10.1177/0748233712452603. Epub 2012 Jul 9.
Formaldehyde (FA) is widely used in industrial and medical settings. It has long been suspected of causing adverse reproductive and developmental effects. However, the effects of exposure to FA on the reproduction are still a matter of scientific controversy. In this study, we evaluate the hypothesis that adverse developmental outcomes of the exposure to FA might be due to its effects on the placental structure. So, histological changes of the placenta in the mice exposed to FA gas were assessed at light and electron microscopy levels. A total of 40 pregnant Balb/C mice were randomly allotted to four groups in which the animals were exposed to FA at the doses of 0 (control), 7, 14 and 28 ppm, respectively, by inhalation, consecutively, for 8 h/d during the organogenesis period. On day 17 of gestation, the animals were killed and the histological specimens of the placentas were taken for light and electron microscopy studies. Also, morphological parameters of the placentas were measured manually. The results showed that the effects of FA on the placenta are not dose dependent. In the FA-exposed mice, an increase in the number and size of trophoblastic giant cells and an enlargement of spongiotrophoblastic cells in the basal zone of placenta were seen. Also, a significant increase in placental weight as well as the ratio of placental to fetal weight but a decrease in the fetal weight were found in the treated groups when compared with those in the control mice (p < 0.05). Moreover, ultrastructural results demonstrated that the diameter of labyrinth interhemal membrane as well as the thickness of trophoblastic basement membranes were significantly increased in the FA-exposed mice. In addition, in the FA-treated animals, a severe accumulation of cytoplasmic droplets in the II and III trophoblastic layers of the placenta were seen. In conclusion, this study may suggest that the exposure to FA during the organogenesis period at doses of 7-28 ppm induces toxic changes in the placental structure. These changes disrupt placental functions and leads to a decrease in the fetal weight.
甲醛（FA）广泛应用于工业和医疗领域。长期以来，人们一直怀疑它会导致不良的生殖和发育影响。然而，接触FA对生殖的影响仍是一个科学争议问题。在本研究中，我们评估了以下假设：接触FA导致的不良发育结果可能是由于其对胎盘结构的影响。因此，在光学和电子显微镜水平上评估了暴露于FA气体的小鼠胎盘的组织学变化。总共40只怀孕的Balb/C小鼠被随机分为四组，在器官形成期，动物分别通过吸入以0（对照）、7、14和28 ppm的剂量连续8小时/天暴露于FA。在妊娠第17天，处死动物并采集胎盘组织学标本用于光学和电子显微镜研究。此外，手动测量胎盘的形态学参数。结果表明，FA对胎盘的影响不依赖剂量。在暴露于FA的小鼠中，观察到滋养层巨细胞数量和大小增加，胎盘基部海绵滋养层细胞增大。此外，与对照小鼠相比，处理组的胎盘重量以及胎盘与胎儿重量之比显著增加，但胎儿重量降低（p < 0.05）。此外，超微结构结果表明，暴露于FA的小鼠中，迷路内血膜直径以及滋养层基底膜厚度显著增加。此外，在FA处理的动物中，在胎盘的II和III滋养层中可见细胞质滴的严重积累。总之，本研究可能表明，在器官形成期以7 - 28 ppm的剂量接触FA会诱导胎盘结构的毒性变化。这些变化会破坏胎盘功能并导致胎儿体重下降。
