Biron D, Dauphin C, Di Paolo T
School of Pharmacy, Laval University, Quebec, Sainte-Foy, Canada.
Neuroendocrinology. 1992 Apr;55(4):468-76. doi: 10.1159/000126158.
The effects of adrenalectomy (ADX) and dexamethasone (DEX) treatment on brain dopamine (DA) receptors of ovariectomized (OVX) rats were investigated by autoradiography using binding of the D1 and D2 antagonists ligands [3H]SCH 23390 and [3H]spiperone, respectively. Fourteen days after ADX, D1 receptors decreased in the middle striatum (M.CPu) and in the dorsal area of the posterior striatum (P.CPu). A more pronounced decrease was observed in the substantia nigra (SN) and no significant changes occurred in the anterior striatum (A.CPu), globus pallidus (GP) and accumbens (Acb). D2 receptors decreased in the M.CPu and dorsal area of the P.CPu and remained unchanged in the A.CPu as compared to OVX rats. Twenty-eight days after ADX, D1 and D2 receptors decreased in the A.CPu (D2), in the M.CPu (D2) and substantially in the SN (D1). DEX treatment (14 days, 0.5 mg/kg, b.i.d., IM, starting 14 days after ADX) reversed these effects in the A.CPu (D2), M.CPu (D2) and SN (D1) when compared to ADX+OVX rats. DEX also increased the density of D1 receptors in Acb, A.CPu and M.CPu when compared to OVX rats. Striatal homogenates of rats treated chronically with ACTH and corticosterone had an increased density of D1 receptors while these treatments alone left these receptors unchanged, thus suggesting either a minor role or no role of the changes in ACTH levels following glucocorticoids manipulations. Our results suggest that the adrenals play a role in the modulation of DA receptors activity in the rat brain.
通过放射自显影法，分别使用D1和D2拮抗剂配体[3H]SCH 23390和[3H]螺哌隆的结合，研究了肾上腺切除术（ADX）和地塞米松（DEX）治疗对去卵巢（OVX）大鼠脑多巴胺（DA）受体的影响。ADX术后14天，中纹状体（M.CPu）和后纹状体背侧区域（P.CPu）的D1受体减少。黑质（SN）中观察到更明显的减少，而前纹状体（A.CPu）、苍白球（GP）和伏隔核（Acb）中未发生显著变化。与OVX大鼠相比，M.CPu和P.CPu背侧区域的D2受体减少，而A.CPu中的D2受体保持不变。ADX术后28天，A.CPu（D2）、M.CPu（D2）和SN（D1）中的D1和D2受体减少。与ADX + OVX大鼠相比，DEX治疗（14天，0.5 mg/kg，每日两次，肌肉注射，ADX术后14天开始）逆转了A.CPu（D2）、M.CPu（D2）和SN（D1）中的这些影响。与OVX大鼠相比，DEX还增加了Acb、A.CPu和M.CPu中D1受体的密度。长期用促肾上腺皮质激素和皮质酮治疗的大鼠纹状体匀浆中D1受体密度增加，而单独使用这些治疗使这些受体保持不变，因此表明糖皮质激素操作后促肾上腺皮质激素水平变化的作用较小或无作用。我们的结果表明，肾上腺在调节大鼠脑内DA受体活性中起作用。
