Differential effects of EEDQ on the dopamine D-1 receptor in vivo and in vitro.
As measured in vitro by means of [3H]SCH 23390 saturation analysis, 5 and 10 mg/kg (i.p., 24 h) of EEDQ caused a 70% reduction and 20 mg/kg and 80% reduction in the numbers of D-1 receptors. In vivo, also measured by [3H]SCH 23390 saturation analysis, 5 mg/kg of EEDQ caused no significant reduction in the D-1 receptor number whereas 10 and 20 mg/kg caused a 40 and 70% reduction, respectively. This difference in sensitivity to EEDQ in vivo as compared to in vitro suggests that EEDQ only destabilizes the D-1 receptor, whereas the inactivation occurs during preparation of the tissue for in vitro binding. Thus, caution should be exercised when animals depleted of D-1 receptors by EEDQ are used for behavioral studies.
Andersen
P H
PH
Department of Biochemical Pharmacology, Novo Industri A/S, Bagsvaerd, Denmark.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D014150:Antipsychotic Agents / Q000378:metabolism; D001552:Benzazepines / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D011804:Quinolines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1
D000317:Adrenergic alpha-Antagonists; D014150:Antipsychotic Agents; D001552:Benzazepines; D011804:Quinolines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; C000470:EEDQ