Profiling neurosteroids in cerebrospinal fluids and plasma by gas chromatography/electron capture negative chemical ionization mass spectrometry
Profiling neurosteroids in cerebrospinal fluids and plasma by gas chromatography/electron capture negative chemical ionization mass spectrometry
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DOI：
10.1006/abio.1999.4384
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发表时间：
2000-01-15
影响因子：
2.9
通讯作者：
Kim, HY
中科院分区：
文献类型：
--
作者：
Kim, YS;Zhang, HJ;Kim, HY
采用气相色谱/电子捕获负化学电离质谱（GC/ECNCI/MS）技术，建立了CSF和血浆中异孕酮（5 α、3 α - thp）及相关神经甾体的定量测定方法。神经甾体被转化为羧基甲氧基肟、五氟苯和三甲基硅基衍生物，并被检测为负离子化学电离过程中产生的强烈（M-181）（-）片段离子。以d(4)-二氢睾酮（DHT）和d(4)-5 α，3 α - thp为内标构建的响应曲线在10 ~ 1000 pg/ml的浓度范围内呈线性关系，在1个月内内标测定的响应比变化小于10%；除黄体酮和二氢黄体酮（DHP）外，大多数神经类固醇的仪器检测限在低picogram范围内，其检测灵敏度比其他类固醇低约10倍。结合固相萃取，该方法可定量测定1-2 ml人脑脊液中至少4种神经甾体激素，包括雄酮、睾酮、5 α、3 α - thp和孕烯醇酮，脑脊液中5 α、3 α - thp的水平与血浆中相当，其他甾体激素水平明显较低。尽管个体脑脊液和血浆样本显示神经类固醇水平差异很大，但物种特异性似乎存在。人脑脊液中5 α、3 α -THP和孕烯醇酮的含量高于猴脑脊液，而猴脑脊液中这些甾体在我们目前的检测限下往往检测不到。与人血浆相比，大鼠血浆样品中雄酮和孕烯醇酮的含量明显低于人血浆，在THP立体异构体中，5 β、3 α -THP和5 α、3 β -THP仅在人血浆中检测到，而5 β、3 β -THP仅在大鼠血浆中检测到。(C) 2000年学术出版社。
A quantitative method for the determination of allopregnanolone (5 alpha,3 alpha-THP) and related neurosteroids in CSF and plasma was established using gas chromatography/electron capture negative chemical ionization mass spectrometry (GC/ECNCI/MS). Neurosteroids were converted to carboxymethoxime, pentafluorobenzyl and trimethylsilyl derivatives and detected as intense (M-181)(-) fragment ions generated under the negative ion chemical ionization process. The response curves constructed using d(4)-dihydrotestosterone (DHT) and d(4)-5 alpha,3 alpha-THP as internal standards showed linearity in the concentration range of 10-1000 pg/ml, The variation of response ratios determined against internal standards over a a-month period was less than 10%, Instrumental detection limits for most neurosteroids were in the low picogram range with the exception of progesterone and dihydroprogesterone (DHP) which were detected with approximately 10 times less sensitivity in comparison to other steroids. In conjunction with solid-phase extraction, this method allowed the quantification of at least four neurosteroids, including androsterone, testosterone, 5 alpha,3 alpha-THP, and pregnenolone in 1-2 ml of human cerebrospinal fluid (CSF), While the level of 5 alpha,3 alpha-THP in human CSF was comparable to that in the human plasma, other steroid levels were significantly lower. Although individual CSF and plasma samples showed widely varying neurosteroid levels, species specificity appeared to exist. The levels of 5 alpha,3 alpha-THP and pregnenolone in human CSF were higher than those of monkey CSF where these steroids were often not detected with our current detection limit, In comparison to human plasma, rat plasma samples contained considerably lower levels of androsterone and pregnenolone, Among THP stereoisomers, 5 beta,3 alpha-THP and 5 alpha,3 beta-THP were observed only in human plasma, while 5 beta,3 beta-THP was detected only in rat plasma. (C) 2000 Academic Press.