Majewska M D, Bisserbe J C, Eskay R L
Brain Res. 1985 Jul 22;339(1):178-82. doi: 10.1016/0006-8993(85)90641-9.
Modulation of binding of [3H]muscimol, a GABAA receptor agonist, by natural and synthetic glucocorticoids was investigated in crude synaptosomal membranes and in brain sections of rat. In adrenalectomized (Adx) rats, muscimol binding was reduced by 30-50% in cerebral cortex, cerebellum, thalamus and hippocampus, as compared to sham-operated controls. This decrease was due to reduced binding affinities of GABA receptors for muscimol. In contrast muscimol binding was increased by 38% in the hypothalamus and did not change in the pons-medulla after Adx. Nanomolar concentrations of corticosterone and pregnenolone-sulfate, but not dexamethasone, enhanced muscimol binding in brain regions that were characterized by reduced binding following Adx. This steroid-induced increase in muscimol binding was due to enhanced affinities of GABA receptors.
在大鼠的粗制突触体膜和脑切片中，研究了天然和合成糖皮质激素对GABAA受体激动剂[3H]蝇蕈醇结合的调节作用。与假手术对照组相比，在肾上腺切除（Adx）大鼠中，大脑皮层、小脑、丘脑和海马体中的蝇蕈醇结合减少了30 - 50%。这种减少是由于GABA受体对蝇蕈醇的结合亲和力降低所致。相比之下，肾上腺切除后，下丘脑的蝇蕈醇结合增加了38%，脑桥 - 延髓中的结合没有变化。纳摩尔浓度的皮质酮和硫酸孕烯醇酮，但不是地塞米松，增强了在肾上腺切除后结合减少的脑区中的蝇蕈醇结合。这种类固醇诱导的蝇蕈醇结合增加是由于GABA受体亲和力增强所致。
