Prominent binding of the dopamine D 3 agonist [ [formula omitted]]PD 128907 in the caudate–putamen of the adult rat

• Published in: Brain research Vol. 822; no. 1; pp. 126 - 131
• Main Authors: Hillefors, Mi, von Euler, Mia, Hedlund, Peter B, von Euler, Gabriel
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.03.1999
• Subjects: Basal ganglia; Binding affinity; Caudate–putamen; Dopamine D 3 receptor; Islands of Calleja; PD 128907; Caudate–putamen; Basal ganglia; Binding affinity; Dopamine D 3 receptor; Islands of Calleja; PD 128907
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(99)01138-5

We have analyzed the binding properties of the selective D 3 receptor agonist [ 3 H ]PD 128907 in 120 days old rats. In tissue sections, we found high numbers of binding sites for [ 3 H ]PD 128907 both in the islands of Calleja and the caudate–putamen ( B max values being 500 and 1000 fmol/mg protein, respectively). The K D values were higher in the caudate–putamen than in the islands of Calleja. Similar regional differences in B max and K D values were observed in membranes from the caudate–putamen and the subcortical limbic region. The distribution of [ 3 H ]PD 128907 in adult rats is markedly different from that observed in young rats. Taken together, the present results suggest a prominent presence of D 3 receptors in the caudate–putamen of adult, but not young, rats. Hence, these findings may have important physiological, pathophysiological, and clinical implications.