Fonlupt P, Bénistant C, Rey C, Lagarde M
INSERM-U205, Laboratoire de Chimie Biologique, Villeurbanne, France.
Mol Cell Biochem. 1993 Jul 7;124(1):51-7. doi: 10.1007/BF01096381.
S-adenosyl-l-methionine (AdoMet) has been reported to affect events linked to noradrenergic neurotransmission. In the present work, we studied the effect of AdoMet on norepinephrine (NE)-stimulated inositol phosphate production in 3H-inositol-labelled crude synaptosomal suspensions of rat brain. AdoMet (50-1000 microM) decreased both the synthesis of labelled polyphosphoinositide (30-50%) and the release of inositol mono- and bisphosphate (40-50%). The AdoMet effect was not dependent on NE concentration (10-1000 microM), suggesting that the inhibition of inositol phosphate release was not the result of a modification of the norepinephrine binding to its receptor sites. S-adenosyl-L-homocysteine (AdoHcy) (1 mM) an inhibitor of methyltransferase activities, partially inhibited (70%) the AdoMet (0.1 mM) effect, indicating that the methylation processes cannot explain all the effects observed. We conclude that, in addition to previously reported effects of AdoMet on NE transport, AdoMet may reduce NE-linked intracellular signalling.
据报道，S-腺苷-L-甲硫氨酸（AdoMet）会影响与去甲肾上腺素能神经传递相关的事件。在本研究中，我们研究了AdoMet对用³H-肌醇标记的大鼠脑粗突触体悬浮液中去甲肾上腺素（NE）刺激的肌醇磷酸生成的影响。AdoMet（50 - 1000微摩尔）可降低标记的多磷酸肌醇的合成（30 - 50%）以及肌醇单磷酸和双磷酸的释放（40 - 50%）。AdoMet的作用不依赖于NE浓度（10 - 1000微摩尔），这表明肌醇磷酸释放的抑制并非去甲肾上腺素与其受体位点结合发生改变的结果。S-腺苷-L-高半胱氨酸（AdoHcy）（1毫摩尔）是甲基转移酶活性的抑制剂，可部分抑制（70%）AdoMet（0.1毫摩尔）的作用，这表明甲基化过程无法解释所观察到的所有效应。我们得出结论，除了之前报道的AdoMet对NE转运的作用外，AdoMet可能会减少与NE相关的细胞内信号传导。
