TABLE 2.

MPD administration alters VMAT-2 immunoreactivity and DA transport velocities in the cytoplasmic and membrane-associated vesicle subcellular fractions.^a

	VMAT-2 immunoreactivityb		DA transport velocityc
	saline	MPD	saline	MPD
cytoplasmic vesicles	174 ± 9	304 ± 9*	2.4 ± 0.3	3.6 ± 0.2*
membrane-associated vesicles	222 ± 13	126 ± 6*	0.20 ± 0.03	0.52 + 0.02*

^aRats received a single administration of MPD (40 mg/kg, s.c.) or saline vehicle (1 ml/kg, s.c.) and were killed 1 h later.

^bMean ± SEM of band density in arbitrary units, N = 4.

^cMean ± SEM of DA transport velocity in units of fmol of DA/(s × μg protein), N = 4. Transport velocities were measured at 600 and 2000 nM DA (i.e., DA concentrations that approximate the K_m in each vesicular fraction⁶) in the cytoplasmic and membrane-associated vesicle fractions, respectively.

^*Indicates a statistical difference, P < 0.05 via a t-test, between saline and MPD-treated groups.