Prominent binding of the dopamine D3 agonist [3H]PD 128907 in the caudate-putamen of the adult rat

• Published in: Brain research Vol. 822; no. 1-2; pp. 126 - 131
• Main Authors: HILLEFORS, M, VON EULER, M, HEDLUND, P. B, VON EULER, G
• Format: Journal Article
• Language: English
• Published: London Elsevier 20-03-1999; Amsterdam; New York, NY
• Subjects: Age Factors; Animals; Autoradiography; Basal ganglia; Benzopyrans - metabolism; Benzopyrans - pharmacology; Binding affinity; Biological and medical sciences; Caudate–putamen; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Dopamine Agonists - metabolism; Dopamine Agonists - pharmacology; Dopamine D3 receptor; Fundamental and applied biological sciences. Psychology; Islands of Calleja; Male; Medicin och hälsovetenskap; Neostriatum - drug effects; Neostriatum - physiology; Olfactory Pathways - drug effects; Olfactory Pathways - physiology; Oxazines - metabolism; Oxazines - pharmacology; PD 128907; Radioligand Assay; Rats; Rats, Sprague-Dawley; Receptors, Dopamine D2 - agonists; Receptors, Dopamine D2 - metabolism; Receptors, Dopamine D3; Tritium; Vertebrates: nervous system and sense organs; Binding; Vertebrata; Agonist; Mammalia; Caudate nucleus; Rat; Rodentia; Central nervous system; Basal ganglion; Putamen; D3 Dopamine receptor; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240; 1872-6240
• DOI: 10.1016/S0006-8993(99)01138-5

We have analyzed the binding properties of the selective D3 receptor agonist [3H]PD 128907 in 120 days old rats. In tissue sections, we found high numbers of binding sites for [3H]PD 128907 both in the islands of Calleja and the caudate-putamen (Bmax values being 500 and 1000 fmol/mg protein, respectively). The KD values were higher in the caudate-putamen than in the islands of Calleja. Similar regional differences in Bmax and KD values were observed in membranes from the caudate-putamen and the subcortical limbic region. The distribution of [3H]PD 128907 in adult rats is markedly different from that observed in young rats. Taken together, the present results suggest a prominent presence of D3 receptors in the caudate-putamen of adult, but not young, rats. Hence, these findings may have important physiological, pathophysiological, and clinical implications.