کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4337062 1295239 2006 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Measurement of kinetically resolved vesicular dopamine uptake and efflux using rotating disk electrode voltammetry
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
Measurement of kinetically resolved vesicular dopamine uptake and efflux using rotating disk electrode voltammetry
چکیده انگلیسی
The vesicular monoamine transporter-2 (VMAT-2) sequesters cytoplasmic dopamine (DA) into vesicles for storage and subsequent release. VMAT-2 activity has traditionally been measured in small synaptic vesicles isolated from rat striatum by monitoring [3H] DA uptake and in cellular expression systems using fast scan cyclic voltammetry. This is the first report using rotating disk electrode (RDE) voltammetry to measure VMAT-2 DA uptake and efflux in small synaptic vesicles. DA uptake profiles followed mixed order kinetics with apparent zero order kinetics for the first 25 s and apparent first order kinetics thereafter. Vesicular DA uptake was temperature- and ATP-dependent and was blocked by the VMAT-2 inhibitor tetrabenazine. Initial velocities of DA uptake were kinetically resolved and displayed Michaelis-Menten kinetics with a Km and Vmax of 289 ± 59 nM and 1.9 ± 0.2 fmol/(s μg protein), respectively. Methamphetamine-induced DA efflux was blocked by tetrabenazine and kinetically resolved with an initial velocity of 0.54 ± 0.08 fmol/(s μg protein). These results suggest that RDE voltammetry can be used to make kinetically resolved measurements of vesicular DA uptake and efflux and will allow the design of experiments that could reveal important information about the kinetics of VMAT-2 activity and its inhibition.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Neuroscience Methods - Volume 155, Issue 1, 15 July 2006, Pages 109-115
نویسندگان
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