- 作者: 洪啟賦
- 作者服務機構: 中國醫藥學院醫學系
- 中文摘要:
Myeloschisis形成的病因仍然是個爭論的問題,目前對Myeloschisis形成的病因有二種不同的說法;一是神經管的
閉合不全,另一是神經管已閉合後再破裂。為了解其形成的病因,作者以掃描式電子顯微鏡觀察服用Ethylenethiourea
(ETU)誘發腰?部有Myeloschisis的大白鼠胎發育過程來探討Myeloschisis形成的病因。
懷孕第十一天大白鼠(Sprague-Dawley)給予每公斤體重240mg單一劑量的ETU,經胃灌食。於服用12小時,24小時
,36小時,48小時後,剖腹取出子宮,置在解剖顯微鏡下,將鼠胎取出。再經系列處理後供掃描式電子顯微鏡觀察其形
成的過程。對照組給予蒸餾水服用,其他過程與實驗組相同。結果對照組正常大白鼠胎的後神經孔(Posterior neuropore)
於懷孕第12.5天完全閉合,形成神經管。實驗組大白鼠胎後神經孔的閉合則受到影響。服用ETU 12小時後(懷孕第11.5
天),後神經孔神經皺襞內緣的神經組織有明顯增生突出。服用24及36小時後,增生的神經組織外翻出後神經孔。服用
48小時後(懷孕第13天)增生外翻的神經組織形成Myeloschisis。
整個Myeloschisis形成過程,後神經孔未曾有閉合過,而是過度增生外翻的神經組織,阻礙後神經孔神經皺襞的閉
合,導致形成Myeloschisis。故Myeloschisis形成的病因,由此研究結果,並不是神經管閉合後再破裂,而是後神經孔
因神經組織過度增生,阻礙其正常閉合而形成。u - 英文摘要: Pregnant Sprague-Dawley rats were utilized in this study. They were separated into two groups. Inthe control group, a single intragastric dose of distilled water was given on the 11th day of gestation. Inthe test group, a single intragastric dose of ethylenethiourea (ETU), 240mg/kg was given on the same dayof gestation. Embryos were recovered 12, 24, 36, and 48 hours after ETU and distilled water administra-tion, and were prepared for scanning electron microscopy and light microscopy. The posterior neuropore of rat fetuses in the control group closed completely on gestation day 12.5.However, the closure of posterior neuropore in ETU-induced fetuses is shown to have been disrupted 12hours after ETU administration. Marked neural tissue overgrowth in the posterior neuropore resulted inneural fold eversion and finally produced a picture of lumbosacral myeloschisis on day 13 of gestation. Our observation implies that myeloschisis is induced by non-closure of the neural fold, not byreopening after its proper closure.
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- 英文關鍵字: --