Effects of rat galanin and galanin message associated peptide (GMAP) on rat growth hormone secretion and stimulating effect of gamma-aminobutyric acid on galanin release from rat hypothalamus.
Immunoreactive galanin and galanin message associated peptide (GMAP) were detectable in rat hypothalamus in the concentration of 563 +/- 23 and 14.3 +/- 3.1 fmol/hypothalamus, respectively. gamma-Aminobutyric acid (GABA) elicited a dose-related increase in galanin release from rat hypothalamic fragments, which was inhibited by picrotoxin, a GABA antagonist. Growth hormone (GH) secretion from rat anterior pituitary cells were stimulated by rat galanin, but not by GMAP. These findings suggest that hypothalamic galanin, but not GMAP, may play roles in GH secretion induced by GABAergic mechanisms in the rat.
Nishiki
M
M
First Division, Department of Medicine, Shimane Medical University, Izumo, Japan.
Murakami
Y
Y
Sohmiya
M
M
Tanaka
J
J
Yamauchi
K
K
Koshimura
K
K
Kato
Y
Y
D000704:Analysis of Variance; D000818:Animals; D018756:GABA Antagonists / Q000494:pharmacology; D019004:Galanin / Q000378:metabolism / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D010852:Picrotoxin / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D018756:GABA Antagonists; D019004:Galanin; D013006:Growth Hormone; D010446:Peptide Fragments; D010852:Picrotoxin; D005680:gamma-Aminobutyric Acid; C078371:galanin message-associated peptide