2. |
- Rinken, A, et al.
(författare)
-
Serotonergic agonists behave as partial agonists at the dopamine D2 receptor
- 1999
-
Ingår i: NeuroReport. - : Ovid Technologies (Wolters Kluwer Health). - 1473-558X .- 0959-4965. ; 10:3, s. 493-495
-
Tidskriftsartikel (refereegranskat)abstract
- RAT dopamine D2short receptors expressed in CHO cells were characterized by activation of [35S]GTPgammaS binding. There were no significant differences between the maximal effects seen in activation of [35S]GTPgammaS binding caused by dopaminergic agonists, but the effects of 5-HT, 8OH-DPAT and 5-methoxytryptamine amounted to 47 +/- 7%, 43 +/- 5% and 70 +/- 7% of the dopamine effect, respectively. The dopaminergic antagonist (+)butaclamol inhibited activations of both types of ligands with equal potency (pA2 = 8.9 +/- 0.1), indicating that only one type of receptor is involved. In competition with [3H]raclopride binding, dopaminergic agonists showed 53 +/- 2% of the binding sites in the GTP-dependent high-affinity state, whereas 5-HT showed only 20 +/- 3%. Taken together, the results indicate that serotonergic agonists behave as typical partial agonists for D2 receptors with potential antiparkinsonian activity.
|
|