. Author manuscript; available in PMC: 2009 Dec 2.

Published in final edited form as: Synapse. 2008 Sep;62(9):700–709. doi: 10.1002/syn.20544

TABLE IV.

Relationship of binding potential to receptor affinity and nondisplaceable uptake PET radioligands for the D_2/3 receptors

Radioligand (reference)	Agonist or antagonist	K_i (nM)^a	K_i: Ratio to MNPA	V_T cerebellum (mL cm^-3)	V_T cerebellum Ratio to MNPA	V_S (mL cm^-3)	V_S: Ratio to MNPA	BP_ND (mL cm^-3)	BP_ND: ratio to MNPA
[¹¹C]MPNA	Agonist	0.17 (a)	1.0	13.97 (b)	1.0	11.18 (b)	1.0	1.03 (b)	1.0
[¹¹C]NPA	Agonist	0.80 (a)	4.7	3.44 (d)	0.2	4.04 (d)	0.4	1.22 (c)	1.2
[¹¹C]PHNO	Agonist	0.14 (e)	0.8	5.81 (f)	0.4	14.63 (f)	1.3	2.7^b(f)	2.6
[¹¹C]raclopride	Antagonist	1.70 (g)	10.0	0.42 (i)	0.03	0.70 (i)	0.1	3.20 (h)	3.1
[¹⁸F]fallypride	Antagonist	0.03 (j)	0.2	0.95 (k)	0.1	29.29 (k)	2.6	23.30 (k)	22.6

K_i values are from rat and mouse. Affinity is the inverse of K_i.

Avg BP_ND value for caudate, putamen, and ventral striatum.

Note: The in vivo values of BP_ND, V_T and V_S come from the following species: [¹¹C]MNPA and [¹¹C]NPA from monkey; [¹¹C]PHNO, [¹¹C]raclopride, and [¹⁸F]fallypride are from human. a) Gao et al., 1990; b) current paper; c) Narendran et al., 2004; d) Hwang et al., 2004; e) Wilson et al.,2005; f) Ginovart et al., 2007; g) Hall et al., 1990; h) Ito et al., 1998; i) Lammertsma et al., 1996; j) Mukherjee et al., 1995; k) Siessmeier et al. 2005.