Galanin increases potassium evoked release of [3H]5-hydroxytryptamine from rat hypothalamic synaptosomal preparations.
The effects of galanin (GAL) have been evaluated on the depolarization evoked release of [3H]5-HT (serotonin or 5-hydroxytryptamine) from rat hypothalamic synaptosomal preparations, using low concentrations of potassium (15 mM). In the same preparation effects of GAL were also evaluated on [3H]5-HT uptake, using kinetic analysis to determine effects on Vmax values and Km values. GAL concentrations of 0.1-10 nM caused a concentration-related increase of the depolarization-evoked release of [3H]5-HT without influencing [3H]5-HT uptake. The results indicate the existence of high affinity GAL receptors on the hypothalamic 5-HT nerve terminals, exerting a facilitatory influence on depolarization-evoked [3H]5-HT release.
Martire
M
M
Department of Pharmacology, Catholic University, Rome, Italy.
Fuxe
K
K
Agnati
L F
LF
Pistritto
G
G
Preziosi
P
P
D000818:Animals; D019004:Galanin; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D010455:Peptides / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D010455:Peptides; D012701:Serotonin; D019004:Galanin; D011188:Potassium