Ruggiero M, Corradetti R, Chiarugi V, Pepeu G
EMBO J. 1987 Jun;6(6):1595-8. doi: 10.1002/j.1460-2075.1987.tb02405.x.
We have studied the effect of gamma-aminobutyric acid (GABA) and other GABA-receptor agonists (3-aminopropanesulphonic acid and muscimol) on the noradrenaline-induced stimulation of polyphosphoinositide metabolism in rat hippocampal slices. Formation of water-soluble inositol phosphates, and polyphosphoinositide metabolism were studied in hippocampal slices prelabelled with [3H]myoinositol. Noradrenaline induced formation of inositol mono-, bis- and trisphosphate during 10 min incubation in the presence of lithium; activation of phospholipase C by noradrenaline was also reflected by the hydrolysis of polyphosphoinositides and by the increased metabolism of phosphatidylinositol. GABA-receptor agonists were unable to activate per se phospholipase C; however, when added together with a low concentration of noradrenaline, they greatly potentiated the noradrenaline-stimulated polyphosphoinositide metabolism. We conclude that GABA-receptor agonists potentiate the effect of noradrenaline on polyphosphoinositide turnover and we discuss the role of this neurotransmitter interaction in the physiology of the hippocampus.
我们研究了γ-氨基丁酸（GABA）及其他GABA受体激动剂（3-氨基丙烷磺酸和蝇蕈醇）对去甲肾上腺素诱导的大鼠海马切片多磷酸肌醇代谢刺激作用的影响。在预先用[3H]肌醇标记的海马切片中研究了水溶性肌醇磷酸的形成及多磷酸肌醇代谢。在锂存在的情况下，去甲肾上腺素在孵育10分钟期间诱导了肌醇单磷酸、双磷酸和三磷酸的形成；去甲肾上腺素对磷脂酶C的激活还表现为多磷酸肌醇的水解以及磷脂酰肌醇代谢的增加。GABA受体激动剂本身无法激活磷脂酶C；然而，当与低浓度的去甲肾上腺素一起添加时，它们会极大地增强去甲肾上腺素刺激的多磷酸肌醇代谢。我们得出结论，GABA受体激动剂增强了去甲肾上腺素对多磷酸肌醇周转的作用，并讨论了这种神经递质相互作用在海马生理中的作用。
