Normal and abnormal embryonic development of the anorectum in rats
Normal and abnormal embryonic development of the anorectum in rats
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DOI：
10.1016/j.jpedsurg.2003.12.002
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发表时间：
2004-04-01
影响因子：
2.4
通讯作者：
Wang, WL
中科院分区：
文献类型：
--
作者：
Bai, YZ;Chen, H;Wang, WL
背景：肛门直肠畸形（ARM）的胚胎学和病理学方面仍然知之甚少。目前尚无公认的理论来解释肛门直肠胚胎学和ARM的异常发育，本研究旨在观察大鼠肛门直肠的发育过程，探讨导致ARM的胚胎发育异常。将正常大鼠胚胎和妊娠12.5 - 20天的ARM胚胎连续矢状切片，并用H & E染色。结果：经ETU处理的ARM大鼠胚胎肛门直肠发育的特点如下：（1）输尿管直肠隔与泄殖腔膜不融合; (2)泄殖腔背膜发育不良。(3)泄殖腔形态异常。(4)尾槽从未出现。所有类型的ARM均为ETU处理的大鼠胚胎的直肠尿道瘘和普通泄殖腔，并在妊娠16天可被识别。缺乏尾沟和泄殖腔背膜发育不良，泄殖腔结构，尿道下裂与泄殖腔膜融合不全是ETU出现直肠尿道瘘或泄殖腔瘘的直接原因。治疗的老鼠
Background: The embryologic and pathologic aspect of anorectal malformation (ARM) remains poorly understood. There is no universally accepted theory to explain anorectal embryology and the abnormal development that produces ARM. The aim of this study was to observe the developmental processes of anorectum in rats and to explore the abnormal embryonic development that leads to ARM.Methods: Rat embryos with ARM were obtained by treating pregnant rats with administration of ethylenethiourea (ETU). Normal rat embryos and embryos with ARM from gestational days 12.5 to 20 were sectioned serially and sagittally and stained with H & E. The relevant structure including cloaca and urorectal septum (URS) were examined in a temporospatial sequence.Results: Characteristics of anorectum development in ARM rat embryos treated by ETU were as follows: (1) URS never fused with cloaca membrane. (2) Dorsal cloacal membrane was maldeveloped. (3) Cloacal configuration was abnormal. (4) Tail groove never appeared. All type of ARM was the rectourethal fistula and common cloaca in ETU-treated rat embryos and was discernible on gestation day 16.Conclusions: Absence of the tail groove and maldevelopment of the dorsal cloacal membrane, cloacal configuration, and urorectal septum are likely to be responsible for the formation of ARM. Failure of fusion of the URS with cloacal membrane is the immediate reason for rectourethral fistula or common cloaca in ETU-treated rats.