Porceddu M L, Giorgi O, De Montis G, Mele S, Cocco L, Ongini E, Biggio G
Life Sci. 1987 Aug 10;41(6):697-706. doi: 10.1016/0024-3205(87)90449-8.
Dopamine-sensitive adenylate cyclase and 3H-SCH 23390 binding parameters were measured in the rat substantia nigra and striatum 15 days after the injection of 6-hydroxydopamine into the medial forebrain bundle. The activity of nigral dopamine-sensitive adenylate cyclase and the binding of 3H-SCH 23390 to rat nigral D-1 dopamine receptors were markedly decreased after the lesion. On the contrary, 6-hydroxydopamine-induced degeneration of the nigrostriatal dopamine pathway enhanced both adenylate cyclase activity and the density of 3H-SCH 23390 binding sites in striatal membrane preparations. The changes in 3H-SCH 23390 binding found in both nigral and striatal membrane preparations were associated with changes in the total number of binding sites with no modifications in their apparent affinity. The results indicate that: within the substantia nigra a fraction (30%) of D-1 dopamine receptors coupled to the adenylate cyclase is located on cell bodies and/or dendrites of dopaminergic neurons; striatal D-1 dopamine receptors are tonically innervated by nigrostriatal afferent fibers.
在将6-羟基多巴胺注射到内侧前脑束15天后，测量大鼠黑质和纹状体中多巴胺敏感的腺苷酸环化酶活性以及3H-SCH 23390的结合参数。损伤后，黑质多巴胺敏感的腺苷酸环化酶活性以及3H-SCH 23390与大鼠黑质D-1多巴胺受体的结合显著降低。相反，6-羟基多巴胺诱导的黑质纹状体多巴胺通路退变增强了纹状体膜制剂中的腺苷酸环化酶活性以及3H-SCH 23390结合位点的密度。在黑质和纹状体膜制剂中发现的3H-SCH 23390结合变化与结合位点总数的变化有关，其表观亲和力未发生改变。结果表明：在黑质内，与腺苷酸环化酶偶联的一部分（30%）D-1多巴胺受体位于多巴胺能神经元的细胞体和/或树突上；纹状体D-1多巴胺受体受到黑质纹状体传入纤维的紧张性支配。
