TABLE 2.

In vitro preincubation of striatal synaptosomes with MDPV is without effect on plasmalemmal [³H]DA uptake

Synaptosomes were preincubated with varying concentrations of MDPV (0–1000 nM) for 1 h at 37°C. Samples were then centrifuged (22,000g for 15 min at 4°C) and resuspended in assay buffer either four or six times and then assayed for [³H]DA uptake as described in the Materials and Methods. MDPV concentrations represent the drug concentration at the time of [³H]DA uptake assay. Values represent means ± S.E.M. (n = 6).

Number of “Washes”	MDPV Preincubation (nM)	[3H]DA Uptake (fmol/μg protein)	MDPV in Synaptosome Preparation after Repeated Washing (nM)
Four	0	1.74 ± 0.09	0
	10	1.95 ± 0.13	0
	100	1.92 ± 0.13	0.20 ± 0.11
	1000	1.96 ± 0.10	0.26 ± 0.11
Six	0	1.27 ± 0.06	0
	10	1.34 ± 0.07	0
	100	1.25 ± 0.06	0.02 ± 0.18
	1000	1.39 ± 0.05	0.09 ± 0.18