Noradrenergic-GABAergic interaction in anterior hypothalamus from normotensive and sinoaortic denervated rats

1. GABA content is decreased in anterior hypothalamus and medulla oblongata of hypertensive rats by sinoaortic denervation (SAD) when compared to control animals which underwent a sham-operation (sham). 2. Lesion of noradrenergic pathways by 6-hydroxydopamine (6-OHDA), intracerebroventricularly administered, induced depletion of noradrenergic content in frontal cortex, anterior and posterior hypothalamus in both SAD and sham-operated rats. 3. As a consequence of this noradrenergic depletion there was an increase of GABA content in anterior hypothalamus only, from sham- and SAD-operated animals, without changes in other areas. 4. There is a noradrenergic-GABAergic interaction in the anterior hypothalamus of normotensive rats which is not impaired in hypertensive rats by sinoaortic denervation.