Effects of ginkgolide B on neuronal discharges in paraventricular nucleus of rat hypothalamic slices / 神经科学通报·英文版
Neuroscience Bulletin
;
(6): 345-350, 2008.
Artigo
em Inglês
| WPRIM
| ID: wpr-264657
ABSTRACT
<p><b>OBJECTIVE</b>To study the central role of ginkgolide B (BN52021) in regulating cardiovascular function of nerve center by examining the effects of ginkgolide B on the electrical activity of rat paraventricular nucleus (PVN) neurons in hypothalamic slice preparation and to elucidate the mechanism involved.</p><p><b>METHODS</b>Extracellular single-unit discharge recording technique.</p><p><b>RESULTS</b>(1) In response to the application of ginkgolide B (0.1, 1, 10 micromol/L; n = 27) into the perfusate for 2 min, the spontaneous discharge rates (SDR) of 26 (26/27, 96.30%) neurons were significantly decreased in a dose-dependent manner. (2) Pretreatment with L-glutamate (L-Glu, 0.2 mmol/L) led to a marked increase in the SDR of all 8 (100%) neurons in an epileptiform pattern. The increased discharges were suppressed significantly after ginkgolide B (1 micromol/L) was applied into the perfusate for 2 min. (3) In 8 neurons, perfusion of the selective L-type calcium channel agonist, Bay K 8644 (0.1 micromol/L), induced a significant increase in the discharge rates of 8 (8/8, 100%) neurons, while ginkgolide B (1 micromol/L) applied into the perfusate, could inhibit the discharges of 8 (100%) neurons. (4) In 8 neurons, the broad potassium channels blocker, tetraethylammonium (TEA, 1 mmol/L) completely blocked the inhibitory effect of ginkgolide B (1 micromol/L).</p><p><b>CONCLUSION</b>These results suggest that ginkgolide B can inhibit the electrical activity of paraventricular neurons. The inhibitory effect may be related to the blockade of L-type voltage-activated calcium channel and potentially concerned with delayed rectifier potassium channel (K(DR)).</p>
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Núcleo Hipotalâmico Paraventricular
/
Farmacologia
/
Técnicas In Vitro
/
Potenciais de Ação
/
Agonistas dos Canais de Cálcio
/
Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)
/
Análise de Variância
/
Ratos Sprague-Dawley
/
Ácido Glutâmico
/
Tetraetilamônio
Limite:
Animais
Idioma:
Inglês
Revista:
Neuroscience Bulletin
Ano de publicação:
2008
Tipo de documento:
Artigo
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