TABLE 3

Radioligand binding and functional activity of DIPT, 5-MeO-DET, and 5-MeO-AMT at monoamine transporters

For test compounds, n = 3–6 for binding and uptake assays, n = 2–4 for release assays. Data are mean ± S.E.M. The standard compounds were, for purposes of comparison, cocaine for the binding and uptake assays, methamphetamine for [³H]dopamine, and [³H]norepinephrine release and p-chloroamphetamine for [³H]serotonin release.

Assay	Drug
Assay	DIPT	5-MeO-DET	5-MeO-AMT	p-Chloroamphetamine	Methamphetamine	Cocaine
HEK-hDAT cells
[¹²⁵I]RTI-55 binding K_i, nM	>10 μM	>10 μM	>10 μM			520 ± 69
Hill coefficient						−0.84 ± 0.06
[³H]Dopamine uptake IC₅₀, nM	>7300^*	>10 μM	2690 ± 940			270 ± 83
[³H]Dopamine release EC₅₀, nM	N.D.	N.D.	N.D.		970 ± 250
Methamphetamine maximal effect, %	Minimal	Minimal	Minimal		100
HEK-hSERT cells
[¹²⁵I]RTI-55 binding K_i, nM	265 ± 21	3520 ± 190	8270 ± 350			277 ± 33
Hill coefficient	−0.82 ± 0.04	−1.29 ± 0.03	−1.96 ± 0.20			−0.88 ± 0.07
[³H]Serotonin uptake IC₅₀, nM	215 ± 72	2990 ± 680	1980 ± 530			320 ± 78
[³H]Serotonin release EC₅₀, nM	N.D.	N.D.	810 ± 380	1350 ± 420	27,800 ± 7700
p-Chloroamphetamine maximal effect, %	Minimal	Minimal	37 ± 10	100	Minimal
HEK-hNET cells
[¹²⁵I]RTI-55 binding K_i, nM	>10 μM	>10 μM	>10 μM			1890 ± 380
Hill coefficient						−0.74 ± 0.04
[³H]Norepinephrine uptake IC₅₀, nM	>8100^*	>10 μM	>10 μM			302 ± 41
[³H] Norepinephrine release EC₅₀, nM	N.D.	N.D.	N.D.		67 ± 18
Methamphetamine maximal effect, %	Minimal	Minimal	Minimal		100

N.D., not determined.
↵* If some experiments yielded IC₅₀ or K_i values less than 10 μM and other experiments yielded IC₅₀ or K_i values more than 10 μM, the latter experiments were assigned a value of 10 μM, and averages were calculated. The actual value is greater than that average, and no standard error is reported.