Table 2.

B_max, K_D, and B_max/K_D values determined in vitro on normal human brain tissue for some protein targets successfully imaged with PET.

Protein	Brain region	Radioliganda	Bmax (nM)	KD (nM)	Bmax/KDb	Reference
5-HT1A	Parahipp. gyrus	[3H]WAY-100635	24±2	1.1±0.2	22	[61]
5-HT4	Caudate	[3H]GR113808	9±2	0.07±0.01	129	[62]
	Caudate	[3H]GR113808	14.9	0.20	75	[63]
5-HT6	Striatum	[125I]SB-258585	22±4	1.3	17	[64]
α4β2nAChR	Cortex	6-[18F]fluoro-A-85380	0.7	0.059	12	[65]
Aβ plaques	Temporal cortex	[11C]PIB	28b	~2	~ 14	[66]
Bz	Neocortex	[3H]Flumazenil	35	6.1	6	[67]
	Temporal cortex	[3H]Flumazenil	70±2	2.2±0.1	32	[68]
		[3H]Sarmazenil	54±2	1.9±0.2	29	[68]
CB1	Frontal cortex	[3H]MePPEP	47±17	0.3±0.1	157	[69]
D1	Caudate	[3H]SCH23390	103±17	2.1±0.6	49	[70]
D2	Putamen	[3H]Raclopridec	8±1	0.9	9	[71]
	Putamen	[3H]Racloprided	9.9±0.9	3.89	3	[71]
	Caudate	[3H]Raclopridee	24±9	2.5±0.2	10	[72]
DAT	Putamen	[3H]RTI-55	52±17	0.10±0.02	520	[73]
GlyT-1	Cortex	[3H]GSK931145	57±7	4.5±0.8	13	[74]
mGluR5	Cortex	[18F]FPEB	25±6	0.11±0.04	230	[75]
Opiate	Frontal cortex	[3H]Diprenorphine	14.8±0.9	0.22± 0.03	67	[76]
NET	Locus coeruleus	[18F](S,S)-FMeNER-D2	35±3	3.6	10	[55]
SERT	Hippocampus	[3H]Citalopram	28±4	3.6±0.8	8	[77]
NK1	Striatum	[3H]GR205171	43±3	0.02	2150	[78]
TSPO	Temporal cortex	[3H]PK11195	71±6	2.9±0.5	24	[79]

^aLigands shown in bold, when labeled with carbon-11 or fluorine-18, have been used for imaging the target protein with PET.

^bRounded to nearest integer.

^cAD brain

^dat 23 °C

^eat 37 °C