N-terminal galanin fragments inhibit the hippocampal release of acetylcholine in vivo.
Using synthetic N-terminal fragments of galanin, galanin (1-7), galanin (1-9), galanin (1-12) and galanin (1-16), we have shown that the minimal sequence required for inhibition of acetylcholine release in vivo from rat ventral hippocampus corresponds to galanin (1-12). The fragment (1-9) displays activity in vivo but only at a very high concentration of 6.23 nmol while galanin (1-7) and C-terminal fragment (17-29) are without effect. Binding studies showed that galanin (1-16) and galanin (1-12) bind with submicromolar IC50 values to rat hippocampal galanin receptors. Galanin (1-9) has substantially lower affinity towards rat ventral hippocampal galanin receptor.
Girotti
P
P
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Bertorelli
R
R
Fisone
G
G
Land
T
T
Langel
U
U
Consolo
S
S
Bartfai
T
T
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D019004:Galanin; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008024:Ligands; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D009479:Neuropeptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D017207:Rats, Sprague-Dawley; D044088:Receptors, Galanin; D011964:Receptors, Gastrointestinal Hormone / Q000187:drug effects / Q000378:metabolism; D012601:Scopolamine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D013329:Structure-Activity Relationship
D008024:Ligands; D009479:Neuropeptides; D010446:Peptide Fragments; D010455:Peptides; D044088:Receptors, Galanin; D011964:Receptors, Gastrointestinal Hormone; D019004:Galanin; D012601:Scopolamine; D000109:Acetylcholine