完整大鼠脑内氚标记去甲肾上腺素代谢的测定

Measurement of tritiated norepinephrine metabolism in intact rat brain.

作者信息

Levitt M, Kowalik S, Barkai A I

出版信息

J Neurosci Methods. 1983 Jun;8(2):155-60. doi: 10.1016/0165-0270(83)90116-4.

Abstract

A procedure for the study of NE metabolism in the intact rat brain is described. The method involves ventriculocisternal perfusion of the adult male rat with artificial CSF containing [3H]NE. Radioactivity in the perfusate associated with NE and its metabolites 3,4-dihydroxymandelic acid (DOMA), 3,4-dihydroxyphenylethyleneglycol (DHPG), 3-methoxy-4-hydroxymandelic acid (VMA), 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), and normetanephrine (NMN) is separated using high-performance liquid chromatography (HPLC). After 80 min the radioactivity in the perfusate reaches an apparent steady-state. Analysis of the steady-state samples shows higher activity in the fractions corresponding to DHPG and MHPG than in those corresponding to DOMA and VMA, confirming glycol formation as the major pathway of NE metabolism in rat brain. Pretreatment with an MAO inhibitor (tranylcypromine) results in a marked decrease in the deaminated metabolites DHPG and MHPG and a concurrent increase in NMN. The results indicate this to be a sensitive procedure for the in vivo determination of changes in NE metabolism.

摘要

本文描述了一种研究完整大鼠脑内去甲肾上腺素（NE）代谢的方法。该方法包括用含[3H]NE的人工脑脊液对成年雄性大鼠进行脑室池灌注。灌注液中与NE及其代谢产物3,4 - 二羟基扁桃酸（DOMA）、3,4 - 二羟基苯乙二醇（DHPG）、3 - 甲氧基 - 4 - 羟基扁桃酸（VMA）、3 - 甲氧基 - 4 - 羟基苯乙二醇（MHPG）和去甲变肾上腺素（NMN）相关的放射性物质，通过高效液相色谱法（HPLC）进行分离。80分钟后，灌注液中的放射性达到明显的稳态。对稳态样本的分析表明，与DOMA和VMA对应的组分中的活性低于与DHPG和MHPG对应的组分中的活性，这证实了二醇形成是大鼠脑内NE代谢的主要途径。用单胺氧化酶（MAO）抑制剂（反苯环丙胺）预处理会导致脱氨基代谢产物DHPG和MHPG显著减少，同时NMN增加。结果表明，这是一种用于体内测定NE代谢变化的灵敏方法。