Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Histamine H3 receptor‐mediated inhibition of depolarization‐induced, dopamine D1 receptor‐dependent release of [3H]‐γ‐aminobutyric acid from rat striatal slices

Histamine H3 receptor‐mediated inhibition of depolarization‐induced, dopamine D1... A study was made of the regulation of [3H]‐γ‐aminobutyric acid ([3H]‐GABA) release from slices of rat striatum by endogenous dopamine and exogenous histamine and a histamine H3‐agonist. Depolarization‐induced release of [3H]‐GABA was Ca2+‐dependent and was increased in the presence of the dopamine D2 receptor family antagonist, sulpiride (10 μM). The sulpiride‐potentiated release of [3H]‐GABA was strongly inhibited by the dopamine D1 receptor family antagonist, SCH 23390 (1 μM). Neither antagonist altered basal release. The 15 mM K+‐induced release of [3H]‐GABA in the presence of sulpiride was inhibited by 100 μM histamine (mean inhibition 78±3%) and by the histamine H3 receptor‐selective agonist, immepip, 1 μM (mean inhibition 81±5%). The IC50 values for histamine and immepip were 1.3±0.2 μM and 16±2 nM, respectively. The inhibitory effects of histamine and immepip were reversed by the H3 receptor antagonist, thioperamide, 1 μM. The inhibition of 15 mM K+‐induced [3H]‐GABA release by immepip was reversed by the H3 receptor antagonist, clobenpropit, Kd 0.11±0.04 nM. Clobenpropit alone had no effect on basal or stimulated release of [3H]‐GABA. Elevated K+ caused little release of [3H]‐GABA from striatal slices from reserpinized rats, unless the D1 partial agonist, R(+)‐SKF 38393, 1 μM, was also present. The stimulated release in the presence of SKF 38393 was reduced by 1 μM immepip to the level obtained in the absence of SKF 38393. These observations demonstrate that histamine H3 receptor activation strongly inhibits the dopamine D1 receptor‐dependent release of [3H]‐GABA from rat striatum; primarily through an interaction at the terminals of GABA neurones. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png British Journal of Pharmacology Wiley

Histamine H3 receptor‐mediated inhibition of depolarization‐induced, dopamine D1 receptor‐dependent release of [3H]‐γ‐aminobutyric acid from rat striatal slices

Loading next page...
 
/lp/wiley/histamine-h3-receptor-mediated-inhibition-of-depolarization-induced-Z6COaI8liF

References (50)

Publisher
Wiley
Copyright
Copyright © 2001 Wiley Subscription Services
ISSN
0007-1188
eISSN
1476-5381
DOI
10.1038/sj.bjp.0704053
pmid
11325806
Publisher site
See Article on Publisher Site

Abstract

A study was made of the regulation of [3H]‐γ‐aminobutyric acid ([3H]‐GABA) release from slices of rat striatum by endogenous dopamine and exogenous histamine and a histamine H3‐agonist. Depolarization‐induced release of [3H]‐GABA was Ca2+‐dependent and was increased in the presence of the dopamine D2 receptor family antagonist, sulpiride (10 μM). The sulpiride‐potentiated release of [3H]‐GABA was strongly inhibited by the dopamine D1 receptor family antagonist, SCH 23390 (1 μM). Neither antagonist altered basal release. The 15 mM K+‐induced release of [3H]‐GABA in the presence of sulpiride was inhibited by 100 μM histamine (mean inhibition 78±3%) and by the histamine H3 receptor‐selective agonist, immepip, 1 μM (mean inhibition 81±5%). The IC50 values for histamine and immepip were 1.3±0.2 μM and 16±2 nM, respectively. The inhibitory effects of histamine and immepip were reversed by the H3 receptor antagonist, thioperamide, 1 μM. The inhibition of 15 mM K+‐induced [3H]‐GABA release by immepip was reversed by the H3 receptor antagonist, clobenpropit, Kd 0.11±0.04 nM. Clobenpropit alone had no effect on basal or stimulated release of [3H]‐GABA. Elevated K+ caused little release of [3H]‐GABA from striatal slices from reserpinized rats, unless the D1 partial agonist, R(+)‐SKF 38393, 1 μM, was also present. The stimulated release in the presence of SKF 38393 was reduced by 1 μM immepip to the level obtained in the absence of SKF 38393. These observations demonstrate that histamine H3 receptor activation strongly inhibits the dopamine D1 receptor‐dependent release of [3H]‐GABA from rat striatum; primarily through an interaction at the terminals of GABA neurones.

Journal

British Journal of PharmacologyWiley

Published: Jan 1, 2001

Keywords: ; ; ; ; ; ; ; ; ;

There are no references for this article.