Fetal development of the mesonephric artery in humans with reference to replacement by the adrenal and renal arteries
Fetal development of the mesonephric artery in humans with reference to replacement by the adrenal and renal arteries
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DOI：
10.1016/j.aanat.2015.07.005
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发表时间：
2015-01-01
影响因子：
2.2
通讯作者：
Fujisawa, Masato
中科院分区：
文献类型：
--
作者：
Hinata, Nobuyuki;Suzuki, Ryoji;Fujisawa, Masato
根据经典的阶梯理论，中肾动脉(MA)具有节段性排列，并在中肾退行性变后仍然存在，其中一些血管成为确定的肾动脉。为了避免血流中断，这样的血管转换需要一个中间阶段，在这个阶段中，两个或更多的节段性MA连接到一条明确的肾动脉。为了研究发育变化，特别是MA节段分布的变化，我们研究了26个人类胚胎(大约5-7周)的连续石蜡切片。5~6周时，每个下胸椎节段均有1~2对MA走行于前外侧或外侧，腰椎各节段有2~5对MA走行，但多不对称。最初的后肾沿主动脉从第一腰椎延伸到第一腰椎，没有动脉供应，尽管它的前面有多个MA。根据肾上腺和后肾大小的增加，MA的数量减少，并限制在从第12胸椎到第二腰椎的水平。MAS的消除首先在后肾的主要下部水平上变得明显。因此，在后肾小球发育之前，假想的动脉阶梯就丢失了。7周时，在MAS完全消除后，后肾上端附近出现一对对称的肾动脉。总而言之，MA似乎没有坚持成为一条明确的肾动脉。(C)2015年爱思唯尔股份有限公司。版权所有。
According to the classical ladder theory, the mesonephric arteries (MAs) have a segmental arrangement and persist after regression of the mesonephros, with some of these vessels becoming definitive renal arteries. To avoid interruption of blood flow, such a vascular switching would require an intermediate stage in which two or more segmental MAs are connected to a definitive renal artery. To examine developmental changes, especially changes in the segmental distribution of MAs, we studied serial paraffin sections of 26 human embryos (approximately 5-7 weeks). At 5-6 weeks, 1-2 pairs of MAs ran anterolaterally or laterally within each of the lower thoracic vertebral segments, while 2-5 pairs of MAs were present in each of the lumbar vertebral segments, but they were usually asymmetrical. The initial metanephros, extending along the aorta from the first lumbar to first sacral vertebra, had no arterial supply despite the presence of multiple MAs running immediately anterior to it. Depending on increased sizes of the adrenal and metanephros, the MAs were reduced in number and restricted in levels from the twelfth thoracic to the second lumbar vertebra. The elimination of MAs first became evident at a level of the major, inferior parts of the metanephros. Therefore, a hypothetical arterial ladder was lost before development of glomeruli in the metanephros. At 7 weeks, after complete elimination of MAs, a pair of symmetrical renal arteries appeared near the superior end of the metanephros. In conclusion, the MAs appear not to persist to become a definitive renal artery. (c) 2015 Elsevier GmbH. All rights reserved.