Retinoic acid-induced lumbosacral neural tube defects: myeloschisis and hamartoma.
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.
Cai
WeiSong
W
Congenital Malformation Lab, Pediatric Surgery, The Second Affiliated Hospital (Shengjing Hospital), China Medical University, Shenyang, 110004, People's Republic of China, cailab9@hotmail.com
Zhao
HongYu
H
Guo
JunBin
J
Li
Yong
Y
Yuan
ZhengWei
Z
Wang
WeiLin
W
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*
D007641:Keratolytic Agents; D013723:Teratogens; D014212:Tretinoin