Open AccessEffect of Neuroactive Peptides on Labeled 5-Hydroxytryptamine Release from Rat Spinal Slices in Vitro
Author(s) -
Huei-Yann Tsai,
Shin Maeda,
Katsuya Iwatsubo,
Reizo Inoki
Publication year - 1984
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.35.403
Subject(s) - neurotensin , somatostatin , chemistry , substance p , medicine , neuropeptide , serotonergic , endocrinology , neurotransmitter , enkephalin , baclofen , serotonin , pharmacology , biochemistry , biology , agonist , opioid , receptor
Effects of neuroactive peptides on the release of labeled 5-hydroxytryptamine (5-HT) from preloaded rat spinal cord slices were investigated. The 5-HT release was significantly stimulated by somatostatin (10-50 microM) and substance P (10-50 microM), but not by neurotensin (50 microM), beta-endorphin (30 microM) and methionine-enkephalin (met-enk) (100 microM). Somatostatin-stimulated 5-HT release was markedly inhibited by gamma-aminobutyric acid (GABA) (30 microM), but not by baclofen (30 microM) and met-enk (100 microM). Substance P-stimulated 5-HT release was strongly inhibited by GABA (30 microM) and baclofen (30 microM), but not by met-enk (100 microM). High concentrations (20 mM) of potassium also stimulated 5-HT release. The high potassium-stimulated 5-HT release was not affected by GABA (30 microM) and met-enk (100 microM). These results suggested further evidence on the important role of somatostatin and substance P as modulators of serotonergic neurones.