Fiber J M, Etgen A M
Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Neurochem Res. 2001 Jul;26(7):853-8. doi: 10.1023/a:1011676505575.
GABAA receptor activation augments electrically-stimulated release of norepinephrine (NE) from rat brain slices. Because this effect is not observed in synaptoneurosomes, GABA probably acts on inhibitory interneurons to disinhibit NE release. To determine whether opioids or adenosine influence GABA-augmented NE release, hypothalamic and cortical slices from female rats were superfused with GABA or vehicle in the presence and absence of 10 microM morphine or 100 microM adenosine. GABA augments [3H]NE release in the cortex and hypothalamus. Morphine alone has no effect on [3H]NE release, but attenuates GABA augmentation of [3H]NE release in both brain regions. Adenosine alone modestly inhibits [3H]NE release in the cortex, but not in the hypothalamus. Adenosine inhibits GABA-augmented [3H]NE release in both brain regions. The general protein kinase inhibitor H-7, augments [3H]NE release in both brain regions and may have additive effects with GABA in cortical slices. These results implicate opioid and adenosine interneurons and possibly protein kinases in regulating GABAergic influences on NE transmission.
GABAA受体激活可增强大鼠脑片电刺激诱发的去甲肾上腺素（NE）释放。由于在突触神经小体中未观察到这种效应，GABA可能作用于抑制性中间神经元，从而解除对NE释放的抑制。为了确定阿片类药物或腺苷是否影响GABA增强的NE释放，在有和没有10微摩尔吗啡或100微摩尔腺苷的情况下，用GABA或溶剂对雌性大鼠的下丘脑和皮质脑片进行灌流。GABA可增强皮质和下丘脑中[3H]NE的释放。单独使用吗啡对[3H]NE释放没有影响，但可减弱两个脑区中GABA对[3H]NE释放的增强作用。单独使用腺苷可适度抑制皮质中[3H]NE的释放，但在下丘脑中则无此作用。腺苷可抑制两个脑区中GABA增强的[3H]NE释放。一般蛋白激酶抑制剂H-7可增强两个脑区中[3H]NE的释放，并且在皮质脑片中可能与GABA产生叠加效应。这些结果表明，阿片类和腺苷中间神经元以及可能的蛋白激酶参与调节GABA能对NE传递的影响。
