Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Characterization and presynaptic modulation of stimulation-evoked exocytotic co-release of noradrenaline and neuropeptide Y in guinea pig heart

Characterization and presynaptic modulation of stimulation-evoked exocytotic co-release of... The relationship between noradrenaline and neuropeptide Y (NPY) release was investigated in the in situ perfused guinea pig heart with intact sympathetic innervation. For determination of NPY concentrations in the perfusate, a specific radioimmunoassay was employed and further characterized. Electrical stimulation of the left stellate ganglion (4, 8, 12, and 50 Hz; for 10 min) evoked a calcium-dependent and frequency-related overflow of noradrenaline and NPY, which was positively correlated (r = 0.83; p < 0.001; n = 25). When two subsequent stimulations (12 Hz; each for 1 min) were performed in the same heart, addition of noradrenaline (10 μM) 5 min prior to the second stimulation reduced NPY overflow by 43 ± 10%. The stimulated release of noradrenaline and NPY was increased by the alpha2-adrenoceptor antagonist yohimbine (1 μM) to 170 ± 10% and 199 ± 26%, and attenuated by the alpha2-adrenoceptor agonist B-HT 920 (1 μM) to 70 ± 9% and 68 ± 9%, respectively. The adenosine analogue cyclohexyladenosine (1 μM) significantly reduced the stimulated overflow of both noradrenaline (to 57 ± 5%) and NPY (to 73 ± 8%). Exogenous NPY (100 nM) attenuated the stimulated overflow of noradrenaline by 30 ± 6%. Uptake1 blockade with desipramine (100 nM) or nisoxetine (100 nM) prior to the second stimulation significantly increased noradrenaline overflow and attenuated that of NPY; the attenuation of the stimulation-evoked overflow of NPY was abolished by yohimbine (1 μM). http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Naunyn-Schmiedeberg's Archives of Pharmacology Springer Journals

Characterization and presynaptic modulation of stimulation-evoked exocytotic co-release of noradrenaline and neuropeptide Y in guinea pig heart

Download PDF
8 pages

Loading next page...
 
/lp/springer-journals/characterization-and-presynaptic-modulation-of-stimulation-evoked-CvmkI6omlB

References (65)

Publisher
Springer Journals
Copyright
Copyright © 1989 by Springer-Verlag
Subject
Biomedicine; Pharmacology/Toxicology; Neurosciences
ISSN
0028-1298
eISSN
1432-1912
DOI
10.1007/BF00165129
Publisher site
See Article on Publisher Site

Abstract

The relationship between noradrenaline and neuropeptide Y (NPY) release was investigated in the in situ perfused guinea pig heart with intact sympathetic innervation. For determination of NPY concentrations in the perfusate, a specific radioimmunoassay was employed and further characterized. Electrical stimulation of the left stellate ganglion (4, 8, 12, and 50 Hz; for 10 min) evoked a calcium-dependent and frequency-related overflow of noradrenaline and NPY, which was positively correlated (r = 0.83; p < 0.001; n = 25). When two subsequent stimulations (12 Hz; each for 1 min) were performed in the same heart, addition of noradrenaline (10 μM) 5 min prior to the second stimulation reduced NPY overflow by 43 ± 10%. The stimulated release of noradrenaline and NPY was increased by the alpha2-adrenoceptor antagonist yohimbine (1 μM) to 170 ± 10% and 199 ± 26%, and attenuated by the alpha2-adrenoceptor agonist B-HT 920 (1 μM) to 70 ± 9% and 68 ± 9%, respectively. The adenosine analogue cyclohexyladenosine (1 μM) significantly reduced the stimulated overflow of both noradrenaline (to 57 ± 5%) and NPY (to 73 ± 8%). Exogenous NPY (100 nM) attenuated the stimulated overflow of noradrenaline by 30 ± 6%. Uptake1 blockade with desipramine (100 nM) or nisoxetine (100 nM) prior to the second stimulation significantly increased noradrenaline overflow and attenuated that of NPY; the attenuation of the stimulation-evoked overflow of NPY was abolished by yohimbine (1 μM).

Journal

Naunyn-Schmiedeberg's Archives of Pharmacology – Springer Journals

Published: Jun 30, 2004

There are no references for this article.