Synthesis and evaluation in rats of homologous series of [ 18 F]-labeled dopamine D 2/3 receptor agonists based on the 2-aminomethylchroman scaffold as potential PET tracers

EJNMMI Research

Table 4 Ex vivo uptake of the evaluated tracers in brain regions and skull bones of rats

Tracer	[¹⁸F]FEt-AMC13		[¹⁸F]FBu-AMC13		[¹⁸F]FEt-AMC15
Treatment	Saline	Raclopride	Saline	Raclopride	Saline	Raclopride
Region	(n = 4)	(n = 4)	(n = 3)	(n = 3)	(n = 3)	(n = 3)
Striatum	0.28 ± 0.03 (1)	0.23 ± 0.08	1.60 ± 0.33 (5)	1.21 ± 0.14	0.02 ± 0.02	0.03 ± 0.01
Hippocampus	0.22 ± 0.02 (2)	0.23 ± 0.08	1.50 ± 0.25 (6)	1.21 ± 0.06	0.03 ± 0.02	0.03 ± 0.01
Thalamus + hypothalamus	0.19 ± 0.003 (4)	0.19 ± 0.05	2.07 ± 0.70 (1)	1.07 ± 0.10	0.03 ± 0.01	0.03 ± 0.01
Cortex	0.18 ± 0.01 (5)	0.16 ± 0.04	1.50 ± 0.32 (7)	1.01 ± 0.11	0.03 ± 0.003	0.03 ± 0.01
Brainstem	0.18 ± 0.02 (6)	0.16 ± 0.04	1.97 ± 0.42 (2)	1.25 ± 0.14	0.03 ± 0.004	0.03 ± 0.01
Olfactory bulbs	0.17 ± 0.01 (7)	0.15 ± 0.04	1.85 ± 0.64 (3)	0.86 ± 0.09	0.03 ± 0.001	0.03 ± 0.02
Rest of brain	0.20 ± 0.02 (3)	0.18 ± 0.03	1.60 ± 0.25 (4)	1.10 ± 0.17	0.02 ± 0.02	0.03 ± 0.02
Cerebellum	0.13 ± 0.01 (8)	0.13 ± 0.02	1.11 ± 0.29 (8)	0.73 ± 0.08	0.03 ± 0.01	0.03 ± 0.01
Mean brain uptake	0.18 ± 0.01	0.16 ± 0.04	1.56 ± 0.33	1.03 ± 0.11	0.03 ± 0.01	0.03 ± 0.01
Pituitary	0.76 ± 0.08	0.59 ± 0.20	3.19 ± 0.29	2.72 ± 0.77	1.36 ± 0.30	1.08 ± 0.27
Parietal bone	0.10 ± 0.01	0.10 ± 0.01	0.61 ± 0.17	0.70 ± 0.18	0.09 ± 0.03	0.08 ± 0.03

Data are presented as means ± standard deviations of standard uptake values. The ranking of the uptake magnitude (highest to lowest) among brain regions within the BBB is shown in parentheses (only for [¹⁸F]AMC13 homologues)