title: Retinoic acid-induced lumbosacral neural tube defects: myeloschisis and hamartoma.
abstract: OBJECTIVE
  To observe the morphological features of the lumbosacral neural tube defects (NTDs) induced by all-trans retinoic acid (atRA) and to explore the pathogenesis of these defects.
  
  
  METHODS
  Rat embryos with lumbosacral NTDs were obtained by treating pregnant rats with administration of atRA. Rat embryos were obtained by cesarean. Fetuses were sectioned and stained with hematoxylin-eosin (H&E). Relevant structures including caudal neural tube were examined. In the atRA-treated rats, about 48% embryos showed lumbosacral NTDs. There appeared a dorsally and rostrally situated, neural-plate-like structure (myeloschisis) and a ventrally and caudally located cell mass containing multiple canals (hamartoma) in the lumbosacral NTDs induced by atRA.
  
  
  CONCLUSIONS
  Retinoic acid could disturb the notochord and tail bud development in the process of primary and secondary neurulation in rat embryos, which cause lumbosacral NTDs including myeloschisis and hamartoma. The morphology is very similar to that happens in humans.
authors.affiliation: Congenital Malformation Lab, Pediatric Surgery, The Second Affiliated Hospital (Shengjing Hospital), China Medical University, Shenyang, 110004, People's Republic of China, cailab9@hotmail.com
authors.forename: WeiSong
authors.initials: W
authors.lastname: Cai
authors.forename: HongYu
authors.initials: H
authors.lastname: Zhao
authors.forename: JunBin
authors.initials: J
authors.lastname: Guo
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: ZhengWei
authors.initials: Z
authors.lastname: Yuan
authors.forename: WeiLin
authors.initials: W
authors.lastname: Wang
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000473:pathology*; D000818:Animals; D047108:Embryonic Development / Q000187:drug effects; D005260:Female; D005865:Gestational Age; D006222:Hamartoma / Q000139:chemically induced* / Q000473:pathology*; D007641:Keratolytic Agents / Q000633:toxicity*; D009436:Neural Tube Defects / Q000139:chemically induced* / Q000473:pathology*; D009672:Notochord / Q000002:abnormalities; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000002:abnormalities / Q000473:pathology; D013122:Spinal Diseases / Q000139:chemically induced* / Q000473:pathology*; D013131:Spine / Q000002:abnormalities* / Q000473:pathology; D013723:Teratogens; D014212:Tretinoin / Q000633:toxicity*
chemical_list: D007641:Keratolytic Agents; D013723:Teratogens; D014212:Tretinoin