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標題: | 補充維生素C或E對大鼠及其孤立核神經元對高海拔低氧反應之影響 The effect of ascorbic acid and α-tocopherol supplement on the responses of rats and their nucleus tractus solitarius neurons to hypobaric hypoxia |
作者: | Ya-Chieh Wu 吳亞潔 |
指導教授: | 曾國藩 |
關鍵字: | 高山症,c-fos,低壓性缺氧,NMDA受器,孤立束核,維生素C,維生素E, altitude sickness,c-fos,hypobaric hypoxia,NR1,NTS,vitamin C,vitamin E, |
出版年 : | 2011 |
學位: | 博士 |
摘要: | 高海拔環境所引發的低壓性缺氧可能引起嚴重傷害的後果。維生素C (vitamin C,主要組成物為抗壞血酸ascorbic acid, AA)與維生素E (vitamin E,主要成分為α-tocopherol, αTC) 這兩種無須處方箋即可取得的抗氧化補充食品對神經組織面對抗氧化壓力時具有保護的效果。本實驗探討從胚胎發育時期施予維生素C或維生素E對成年動物對抗低壓性缺氧時是否具有保護效果。孤立束核為負責心肺功能反應路徑上的神經核。形態學上,本實驗以孤立束核內神經細胞的c-fos以及N-甲基-D-天門冬胺酸鹽 (N-methyl-D-aspartate; NMDA) 接受器次單位NR1的表現情形為指標,檢視維生素的補充是否對此核區有保護作用。發現正常氧壓下,補充維生素C與維生素E皆減少幼鼠或成鼠NTS中表現c-fos的神經細胞數目,同時也抑低NR1的表現。此外,維生素C與維生素E的施予也顯著降低了受低壓性缺氧處理的成鼠孤立束核中神經細胞內c-fos與NR1的表現;這同時還減緩大鼠在低壓性缺氧時的焦慮行為。上述c-fos表現抑低的現象集中在孤立束核內負責接收化學受器,壓力受器以及氣管支氣管樹神經訊息的特定次核區內。這些現象並不出現在缺氧前一週才開始施予維生素C或維生素E的成鼠上,顯示從胚胎發育時期開始持續補充維生素C或維生素E可能改變了孤立束核內細胞的特性、環境或細胞間的連結等,進而改善動物在低壓性缺氧時的反應。本實驗的結果顯示從胎兒開始持續補充維生素C或 E可能做為增強動物從小到大對缺氧耐受性的作法。 Hypobaric hypoxia, encountered at high altitude, could result in severe consequences. Ascorbic acid (AA) and α-tocopherol (αTC), the two readily available over-the-counter antioxidants, are known to protect nervous tissue against oxidative stress. Here we study whether AA or αTC supplement starting prenatally protects animals against hypobaric hypoxic challenge at adulthood. Expressions of c-fos and the NR1 subunit of the N-methyl-D-aspartate receptors in the nucleus tractus solitarius (NTS) subserving cardiorespiratory functions were investigated. AA and αTC supplement reduced the number of c-fos immunoreactive neurons and intensity of NR1 expression in young and adult animals under normoxia. The treatment, in addition, attenuated the activation of NTS neurons, in terms of c-fos and NR1 expressions, and reduced the anxiety behaviors of adult rats subjected to hypobaric hypoxic challenge. Reduction of c-fos immunoreactive neurons was found concentrated in the chemoreceptor, baroreceptor and tracheobronchial tree NTS subnuclei that receive corresponding afferents. The protective effect was not found in normal adult animals supplemented with AA or αTC a week before hypobaric hypoxic challenge. In short, prenatal and sustained AA or αTC supplement altered NTS substrate and ameliorated animals’ reactions to hypobaric hypoxic insult, suggesting that this may be considered to protect animals from hypoxic insults from young to adult. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/48555 |
全文授權: | 有償授權 |
顯示於系所單位: | 解剖學暨細胞生物學科所 |
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