Cargando…
Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion
The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 (3~30 µM), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and...
Autores principales: | , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Korean Physiological Society and The Korean Society of Pharmacology
2014
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4211128/ https://www.ncbi.nlm.nih.gov/pubmed/25352764 http://dx.doi.org/10.4196/kjpp.2014.18.5.431 |
_version_ | 1782341515454971904 |
---|---|
author | Lim, Hyo-Jeong Lee, Hyun-Young Lim, Dong-Yoon |
author_facet | Lim, Hyo-Jeong Lee, Hyun-Young Lim, Dong-Yoon |
author_sort | Lim, Hyo-Jeong |
collection | PubMed |
description | The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 (3~30 µM), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and time-dependent fashion. Rb2 (10 µM) also time-dependently inhibited the CA secretion evoked by DMPP (100 µM, a selective neuronal nicotinic receptor agonist) and high K(+) (56 mM, a direct membrane depolarizer). Rb2 itself did not affect basal CA secretion (data not shown). Also, in the presence of Rb2 (50 µg/mL), the secretory responses of CA evoked by veratridine (a selective Na(+) channel activator (50 µM), Bay-K-8644 (an L-type dihydropyridine Ca(2+) channel activator, 10 µM), and cyclopiazonic acid (a cytoplasmic Ca(2+)-ATPase inhibitor, 10 µM) were significantly reduced, respectively. Interestingly, in the simultaneous presence of Rb2 (10 µM) and L-NAME (an inhibitor of NO synthase, 30 µM), the inhibitory responses of Rb2 on ACh-evoked CA secretory response was considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of Rb2-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of Rb2 (10 µM) was greatly elevated compared to the corresponding basal released level. Collectively, these results demonstrate that Rb2 inhibits the CA secretory responses evoked by nicotinic stimulation as well as by direct membrane-depolarization from the isolated perfused rat adrenal medulla. It seems that this inhibitory effect of Rb2 is mediated by inhibiting both the influx of Ca(2+) and Na(+) into the adrenomedullary chromaffin cells and also by suppressing the release of Ca(2+) from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade. |
format | Online Article Text |
id | pubmed-4211128 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | The Korean Physiological Society and The Korean Society of Pharmacology |
record_format | MEDLINE/PubMed |
spelling | pubmed-42111282014-10-28 Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion Lim, Hyo-Jeong Lee, Hyun-Young Lim, Dong-Yoon Korean J Physiol Pharmacol Original Article The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 (3~30 µM), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and time-dependent fashion. Rb2 (10 µM) also time-dependently inhibited the CA secretion evoked by DMPP (100 µM, a selective neuronal nicotinic receptor agonist) and high K(+) (56 mM, a direct membrane depolarizer). Rb2 itself did not affect basal CA secretion (data not shown). Also, in the presence of Rb2 (50 µg/mL), the secretory responses of CA evoked by veratridine (a selective Na(+) channel activator (50 µM), Bay-K-8644 (an L-type dihydropyridine Ca(2+) channel activator, 10 µM), and cyclopiazonic acid (a cytoplasmic Ca(2+)-ATPase inhibitor, 10 µM) were significantly reduced, respectively. Interestingly, in the simultaneous presence of Rb2 (10 µM) and L-NAME (an inhibitor of NO synthase, 30 µM), the inhibitory responses of Rb2 on ACh-evoked CA secretory response was considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of Rb2-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of Rb2 (10 µM) was greatly elevated compared to the corresponding basal released level. Collectively, these results demonstrate that Rb2 inhibits the CA secretory responses evoked by nicotinic stimulation as well as by direct membrane-depolarization from the isolated perfused rat adrenal medulla. It seems that this inhibitory effect of Rb2 is mediated by inhibiting both the influx of Ca(2+) and Na(+) into the adrenomedullary chromaffin cells and also by suppressing the release of Ca(2+) from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade. The Korean Physiological Society and The Korean Society of Pharmacology 2014-10 2014-10-17 /pmc/articles/PMC4211128/ /pubmed/25352764 http://dx.doi.org/10.4196/kjpp.2014.18.5.431 Text en Copyright © 2014 The Korean Physiological Society and The Korean Society of Pharmacology http://creativecommons.org/licenses/by-nc/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Article Lim, Hyo-Jeong Lee, Hyun-Young Lim, Dong-Yoon Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion |
title | Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion |
title_full | Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion |
title_fullStr | Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion |
title_full_unstemmed | Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion |
title_short | Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion |
title_sort | inhibitory effects of ginsenoside-rb2 on nicotinic stimulation-evoked catecholamine secretion |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4211128/ https://www.ncbi.nlm.nih.gov/pubmed/25352764 http://dx.doi.org/10.4196/kjpp.2014.18.5.431 |
work_keys_str_mv | AT limhyojeong inhibitoryeffectsofginsenosiderb2onnicotinicstimulationevokedcatecholaminesecretion AT leehyunyoung inhibitoryeffectsofginsenosiderb2onnicotinicstimulationevokedcatecholaminesecretion AT limdongyoon inhibitoryeffectsofginsenosiderb2onnicotinicstimulationevokedcatecholaminesecretion |