Inhibition of striatal dopamine transporter activity by 17beta-estradiol.

Title

Inhibition of striatal dopamine transporter activity by 17beta-estradiol.

Creator

Disshon K A; Boja J W; Dluzen D E

Publisher

European journal of pharmacology

Date

1998
1998-03

Description

Striatal synaptosomes from ovariectomized rats were prepared to examine the effect of 17beta-estradiol on [3H]dopamine uptake. Estradiol inhibited [3H]dopamine uptake in a dose-dependent manner, with an IC50 of 7.2 microM. Use of identical concentrations of progesterone had no effect on [3H]dopamine uptake. The effects of estradiol were exerted by decreasing the affinity of the transporter for dopamine, as revealed by a dose-dependent increase in the Km. The Km values for 0 (control), 10, and 100 microM estradiol were 108+/-11 258+/-44 and 415+/-40 nM, respectively, with each of the three concentrations tested being significantly different among each other. No statistically significant differences were obtained for the Vmax, with values for the three increasing doses being 9.2+/-0.8, 8.3+/-0.5 and 7.3+/-0.8 pmol/min per mg protein. These results demonstrate that estradiol, but not progesterone, inhibits striatal dopamine uptake by decreasing the affinity of the transporter for dopamine. Such a mechanism may serve as one of the bases for the modulatory effects of estradiol upon the nigrostriatal dopaminergic system.

Subject

Female; Animals; Rats; Dopamine/metabolism; Neostriatum/*drug effects/metabolism; Dopamine Plasma Membrane Transport Proteins; *Membrane Glycoproteins; *Nerve Tissue Proteins; Estradiol/*pharmacology; *Membrane Transport Proteins; Carrier Proteins/*antagonists & inhibitors; Synaptosomes/*drug effects/metabolism; Sprague-Dawley

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

207–211

Issue

2

Volume

345

Citation

Disshon K A; Boja J W; Dluzen D E, “Inhibition of striatal dopamine transporter activity by 17beta-estradiol.,” NEOMED Bibliography Database, accessed September 23, 2021, https://neomed.omeka.net/items/show/5371.

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